Kelly and Ponch: The large valve heads does not equate to Stage 1 in the full size cars. It does equate to 455 HP (which is short for High Performance, and the way Buick listed it in their documentation oftentimes). Ricks documentation verifies everything I said........except for one thing, but I'll address that in a minute. Kelly, You've misread my posts above. I said all 71 & 72 Riv GS cars did have the large valve heads. But having large valve heads does not mean Stage 1. It does mean you have at least a 455 HP. Of course the Stage 1 also used the large valve heads. The 455 HP and the Stage 1 both used the large valve heads. I think whats happening here, you're mistaking large valve heads for Stage 1 only. There is no correct codes for Stage 1 heads. They're all just regular castings that Buick machined for the larger valves. You could have had a 72 Riv GS with the Stage 1 option, as it was a mid year offering. But in 71 the Stage 1 option was not offered on the Riv, with the GS option or not. The base Riv GS engine was the 455 HP (they called it "modified" this year), and you got the large valves. You had to order the GS option to get that engine. Regular Rivs got the std. engine. Ponch, three rings IS 455 HP and not Stage 1. If as you say three rings equals Stage 1, then what does 1 ring mean? They did not offer separate camshafts for the Stage 1 option depending on what car it was going into. Stage 1 cam has one ring regardless of application. 2 rings Stage 2 and three rings 455 HP (only available on full size cars). The 455 HP cam had more lift and less duration to give the large cars more low rpm torque. They didn't put the 3 groove cams in a Stage 1 and the they didn't put single groove cams in the 455 HP. Only the full size cars got the 3 ring cams. I didn't get my info. from just reading, I'm pretty much caught up in the info/tech junkie mode.....with grease. Misinterpretation of whats said is pretty easy, as evidenced from previous posts. Time has a way of altering perceptions and memory. We are all suseptible to that. As to fuel pumps. The only true Stage 1 application for the large body pumps is the 69 GS Stage 1, as the regular 400 cars used the smaller bodied pumps. Seems all the large body pumps are described as Stage 1 pumps, but that just isn't true. 70 thru 74 GS 455 A-body cars also used the large body pumps. 69 & 70 Riv GS used electric intank pumps. 71-74 full size cars used the regular pumps, same pump as used from 67-69 400/430. Finding a 455 with a large body pump really doesn't mean much nowadays as most likely that pump has been changed sometime in the past, several times over. The only thing I disagreed on with Ricks article was the statement that the 71 & 72 Riv GS came std. with the Stage 1 engine. It didn't. It did come with the large valve 455 HP (called "modified" engine those two years), but that is a different engine than a Stage 1. The Stage 1 option was a mid year 72 offering on the Riv GS. Otherwise Ricks article was right on.....as usual :TU:
So in a nut shell the 1971 and 1972 Buick Chassis Service Manuals call the larger valve heads "HP" option for the 1971 and early 1972 Rivs. The late 72's was the change over. In 1973 Buick changed the "HP" designation to "Stage 1" for the Riviera as stated in the 1973 Chassis Service Manual. Am I correct to say this? I'll buy that. When you look at the 1971 and 1972 Riviera GS's there are no Stage 1 badges. Yet in 1973 Buick added the Stage 1 emblem along with a seperate engine package listed called the Stage 1. Which further explains the chassis manual name change for 1973. Now regarding the engines the cams were different for the HP compared to the Stage 1 big car cams? Maybe Buick did this because of lagging sales that the Buick gurus desided to change the performance "HP" name to attract younger buyers calling it a Stage 1 option, being the HP rating was dropping. Now for simple discussion. What would be the difference between the "HP" heads compared to the Stage 1 heads this ONLY relating to the big cars and performance not emisions. I say "big cars", because as we know a few Centurions came out with that "HP" engine as none had any designated Stage 1 badges. If there is no change then the only difference from what I am gathering here is the cam. I did check the 1973 Chassis Service book page OA-6 and in the production codes in the 5th digit VIN "U" meant standard 455 with engine block code XF VIN "V" meant (A) series (Skylark GS) dual exhaust Stage 1 with engine block code XS VIN "W" meant (E) series (Riviera) Stage 1 dual exhaust with engine block code XA So in 1973 as you stated correctly it was called the Stage 1 option. Lastly does anyone have a 1971, 1972 and 1974 Buick chassis manual that can look up and scan the engine codes and vin designations. Also part numbers, does anyone have the part numbers for the 1971-72 HP cam "E" series and the part number for the 1973 and up Stage 1 cam "E" Series. I would like to compare the cam part numbers to the ones I posted. I would like to take all this added info and update my article cause every few months this questions comes up and one post can then answer all questions. Great thread guys very informative! :TU:
Rick: This is a good discussion. Hashing all this out will definitely make things more black and white, we don't want any gray areas. Been enough of that over the years. The HP option included the large valve heads. This was the std. engine in the Riv GS in 71 & 72. Mid year 72 the Stage 1 option became available on the Riv GS, not available in 71. Something I cannot verify was 1973 options. But using the parts book as a reference and something I think is correct is that 73 & 74 the options in this regard are the same between the two years. Using 74 info. they list the Stage 1 as a separate option on the Riv. Which would lead you to believe that it had a base engine other than that option. Then when going through the parts book, it lists separate camshafts for the E series (Riv) if it had the GS option, base 455 option or Stage 1 option. I'll include the part numbers and copies of the 74 option lists for the full size cars. It'll take a couple posts, I hope they come through clear. Below the camshafts are listed. 69-74 400-430-455 Eng. (Stage 1)........................1383853 70 455 Eng. exc. Stage 1................................1237665 70-71 455 Eng. (Stage 1) package........................1394519 70-71 455 Eng. (Stage 2) package........................1394520 67-71 400-430-455 (Stage 2)..............................1385557 71-74 All E (GS) & B (HP) (455 Eng.).....................1237664 71 455 Eng. less E (GS) & (Stage 1).................1237665 72-74 455 Eng. Less E (GS) & (Stage 1).................1239629 And yes, the HP cam and Stage 1 cams were different. Many years ago I measured several of each and both duration and lift were different. The HP cams always had more lift and less duration and if memory serves me were ground on wider lobe sep angles. The heads are the same between HP and Stage 1. Larger valves than the standard 455 heads. So I guess when it comes to full size cars we should not call large valve heads Stage 1, but just simply large valve heads. The HP 455 was optional on the Centurion starting in 71 and std. on the Riv GS that year. Same for 72. Below is listed 71 ratings for the three 455 engines. 455 std. engine: 315 h.p. (gross rating), 230 h.p. (net rating) & (255 h.p. w/ dual exh.) 450 ft. lbs. torque (gross rating), 365 ft. lbs. (net rating), 380 ft. lbs. (dual exhaust) 455 HP engine: 330 h.p. (gross rating), 265 h.p. (net rating) this engine included dual exhaust, 455 ft. lbs. torque (gross rating), 385 ft. lbs. (net rating) 455 Stage 1 engine: 345 h.p. (gross rating), 275 h.p. (net rating), 460 ft. lbs. torque (gross rating), 395 ft. lbs. torque (net rating) I believe the HP engine came in the Riv GS as the base engine starting in 1971 and continued through the 74 model year. With the Stage 1 an option starting in mid year 72 and continuing through the 74 model year. 75 the GS option was a handling/trim option. This is not saying they changed the HP designation in 73 to include the Stage 1 option. The top engine option (Stage 1) remained an extra cost option on the Riv GS. Otherwise all Riv GS cars in 73 and 74 would be Stage 1 cars, and they are not. Very few actually had the Stage 1 grille emblem those two years. Do we have any DCR's on the full size cars? We could nail it down and put this pup to bed for sure then. Take a look at the next few posts with the copies of the printed options along with the costs and codes. This is for 74. Wish I had the 73 info. to verify it was identical. So this small aspect will remain in question (73) or gray til then. Oh and by the way, I finally did make some more fiberglass bumpers for my 70 Stage 1. The molds finally were useful again.
Does anyone have any actual proof (documentation) that there was a mid year engine option available on the 72 Rivs without a eum daily reports, and they say that the number of 72 Rivs with the GS option -A9, (2171), plus the number of Rivs with the standard 455 -L74 (31557) adds up to the total number of 72 Rivs (33728). So according to Buick, who should know best, all the non GS 72 Rivs used the regular 455. If Buick offered the HP 455 without the GS option on a 72 Riv, the buyer wouldn't have gotten the 3.42 positraction which would have wasted the higher RPM potential of the HP 455.
Great! Post away please :TU: Also here is a page from the ROA on production numbers for the Riv's , note that for 71 and 72 no Stage 1 option was offered. So now thats is set in stone, as there was no Stage 1 option for 71 and 72 as it was a 455 with an HP option. Cool What do you need for a '73 as I owned one for 6 years did a lot of checks with it. It was a GS Riv and it had the small valve heads and the standard cam. http://www.rivowners.org/features/productn.html
Agreed, that would be helpful. I have none as I thought it was for the entire 72 model year changing over for '73. But you never know as GM has done this type of mid year changes before, it would just be helpful to get documents on this.
Carl: I have the sales code info with pricing for the early 72 Buicks all series. I also have this info for the 70, 71 and 74 cars. I thought they didn't offer the Stage 1 option on the 72 either until I was shown the paperwork with sales codes and pricing from a mid year publication. Mine doesn't show it as its an early production print. I'll email George N. and see if he kept the email that was sent with a photocopy of that page showing the Riv GS with the Stage 1 option being available. I think it was George Toth that had the copy. I'll do some digging as I know there some skepticism on this subject. Which I think is good. Without proof its just another rumor. This is true, the Stage 1 option (A-1) production numbers would have been included in the entire Riv GS production numbers. You couldn't order the Stage 1 option without the Riv GS option. The std. 455 engine would have been included in the regular Riv numbers. Yup, see above. That's the whole point. They didn't offer the 455 HP without the GS package in the Riv. You had to order the GS package on the Riv to get the 455 HP. You could get the 455 HP on the Centurion as an upgrade option. And interestingly enough if you got the 455 HP on the Centurion you automatically got dual exhaust. Now I'll spill the beans.....years ago when I used to spend way too much time out in the wrecking yards, if I found a Centurion with dual exhaust (factory) then I knew it had the 455 HP and big valve heads. Darn secrets........slipping out. The 455 HP didn't utilize higher rpm to accomplish better performance, it used higher torque at a lower rpm. That's why they used higher lift and less duration to move the torque curve down lower on the rpm scale. You could order the 3.42 positraction rearend option on any of the full size cars except the Electra. Strangely enough you had to have dual exhaust to get those gears. You're a tough egg to crack there Carl.........that's a good thing. Stand up for something or fall for anything as they say. :TU: Does any of this work for you....... uzzled:
Ponch, By all means this thread is no where near any nasty debates like the BD Block and Edelbrock Heads thread. I find this as a very civil informative discussion on trying to research the questions of the Stage 1 and the HP 455 options. I though I knew most of the info and what I like now is that I am still learning that there is more info out there. Someone said in this thread that now we can get the facts and "put this puppy to bed" I agree. So you shouldn't say that you didn't mean to open up this debate. It's good that you did. In the end we will all learn something from it and best of all we are all acting like adults doing so. :TU: I for one will be collecting all the info, and documentation I can get so that a factual sheet, article what ever you want to call it, can be made up for everyone to use. Maybe a sticky on this topic and also send it to the other Buick sites as basic information and identification on these years and cars.
I have been told in the past that a 73 Riv (not GS) might have large valve heads. But after reading Most of all these posts, I assume that was wrong. It had to be a GS or Stage Riv to have large valve heads. Right?
Yes they can. For the 1973 model you have to check the 5th digit in the VIN will tell you if it has the (large valves) Stage 1 option. It can still be a GS Riv but a non Stage 1 Small valve heads) and it could be a Stage one (large valve heads) optioned non GS Riv. Or just a plain Riv with no GS or Stage option (small valves)
Ponch: I don't know what the ZA code stands for. But it must stand for the HP option for that year and model car it came in. Those are the large valve heads though. :TU: Thats a good thing. Rick: The HP option came standard on the Riv GS starting in 1971. I don't think you could opt out and get the regular 455 with the small valve heads on the Riv GS's. At least it doesn't show you could order it that way. The 455 HP engine was first introduced in 1971 and had the large valve heads. Same heads as the Stage 1, but a different engine, with different codes. So that being said, just having large valves does not mean Stage 1. It just means either HP or Stage 1. The 5th digit will designate Stage 1. There was no VIN designation for the 455 HP. In addition you couldn't order the Stage 1 option on the regular Riv cars, you had to get the Riv GS to get that top engine option. I'm still waiting on getting copies of the mid year 72 pricing, codes and options showing the Riv GS Stage 1 option for 72. I have the early production printing, which does not show it available, but have seen copies of the mid year printing which does show it. I think he also has the 73 printing which shows the codes and pricing, and I have the 74 printing. When I get that info. I'll pass it along.
I think we are starting to beat a dead horse here and all (me included0 should go back and re-read this entire thread. Regarding the quote, my post was regarding the 1973 model year, not the 71 and 72 years. I did learn though from this thread that for 1971 and 72 use to think the HP option was the same as the stage 1 option. It is similar, but Buick had it classified as a HP option and not a Stage 1 option and it was slightly different, I agree now after reading that and researching that for the 1971 and 1972 years. But for the 1973 Riviera below is pointed out. First to define things for 1973 year: Buick divided the Stage 1 Option and the GS option. There was no HP option in 1973, it was called the Stage 1 option and if you look back at my ealier post I broke down what the option gets you. If is is called an HP option that is news to me and I would like to see documentation on that as I have not seen any. For the 1973 and this I know is fact: You can order an standard 455 Riviera, 5th VIN is a "U" will have block stamped "XF" (small valve heads) You can order a Riviera with the GS option and with NO Stage 1 option VIN 5th digit will have "U" with a block stamped XF (mine had this and also had the small valve heads) You can order a Riviera with the Stage 1 option and NO GS option VIN 5th digit will have a "W" with block stamped XA (large valve heads) You can order a Riviera with the Stage 1 option AND the GS option VIN 5th digit will have a "W" with a block stamped XA (large valve heads) My info (regarding the 1973 model) was not only first hand visual on 1973 boattails (I did own a '73 GS Riviera), but also from the 1973 Buick Chassis Manual, The ROA Club, and information gathered from Dennis Manner
Back when I was in college, my friend Darren's mom bought a '73 Boattail, non-GS with a Stage 1 grille emblem. It ran like it was a Stage 1....Dan
I have a 71 GS Riv motor in my 69 Lark and the engine is stamped TA. It did come with the Stage 1 heads.
I have ? on this topic. When I pulled my 71 GS (skylark) motor apart. It had all of the 71 Riv parts in it. You all call it HP. The window sticker has A9 - 455 High perforamce. Well did they screw up or am I crazy?
