I am thinking off buying the heads off a 455 electra from a junkyard. I pulled this number off the inside of the door on a sticker. If it is the vin can you guys decode it for me, Specifically the engine. 4N573H585002
That looks like a 73` Lesabre custom you have there with a 350-2bbl engine.Do you have the VIN from the drivers side dash?? How many valve cover bolts?? Later,Tony.
4N573H585002 how are you pulling the engine code off of this #? it looks to me like Flint, MI production with a missing engine code. 4 = Buick N = Le Sabre Custom 57 = 2dr hardtop sport coupe ? = engine code 3 = 1973 H = Flint, MI 585002 = sequential production # of course, an 'H' in the 5th position would code to a 350 2v which is possible. codes for a 455 would be: T = base U = dual exhuast V = stage 1 W = riv a 455 has 5 bolt valve covers a 350 has 6 bolts.
No, The car this came from is a fullsize electra, not to sure. What I am sure off is that it is fullsize and has a 455 in it. Just would like to know the year or any info I can get. The number came from a decal plate on the end of the drivers door. I know it wasn't a 350 from the engine as well as the 455-4 intake sticker. The reason I would like to know is I have a 1975 455 from an electra that I want to get the compression up on. I heard that in 75 the compression drop is from the mainly form the heads and not to much dished pistons. So I was told if I find 74 or earlier heads and put them on I will get closer to 10.1 compression. Does this sound right to you guys or was my informant tallking out of his A##.
As Bob and I posted earlier,check the VIN # on the LS of the dash (viewed from outside the car,near the hood) the #5 position designates the engine,#6 the year.In regards to the valve cover bolts 455`s have 5,pretty sure 350`s use only 4.The 75-76 455 blocks are supposed to be better.I would think a set of 73 heads would be sufficient (older would be better,newer not so good). You probably will need some pistons/headwork to get near 10.1 compression.You can make a 73 455 run pretty good on 8.5 compression pump gas if you do your homework and pick the right parts.Later,Tony.
So I was told if I find 74 or earlier heads and put them on I will get closer to 10.1 compression. the 75/76 engines have 7.9:1 compression with 78cc open chamber heads. the 71/74 engines have 71cc closed chamber heads, so yes, you can bump compression a decent amount by swapping. i don't know exactly how much that calcs to ... i think 10.0:1 is a little optimistic without machine work or new small dish pistons. the 1970 engines had 10.0:1 and smaller piston dish yet and only 69cc combustion chambers. of course, installing the Stage 1 valves will also help to drop compression and you can do that as well. in 75 the compression drop is from the mainly form the heads and not to much dished pistons. the 75/76 pistons have a smaller dish than the 71/74 pistons but this is misleading because they also have a shorter pin height. this means that for compression purposes they are approx equal but the 75/76 pistons SUCK for quench. In regards to the valve cover bolts 455`s have 5,pretty sure 350`s use only 4. the 215 / 300 / 340 use 4 bolt valve covers. the 350 is a bored 340 but Buick also swapped the valve order. the 6 bolt valve covers are one of the ways to tell the difference between a 350 and one of the earlier small block engines. http://www.taperformance.com/newpage1.htm all Chevy small blocks use 4 bolt valve covers, older ones around the perimeter of the cover like SB or BB Buicks and newer ones with 4 bolts in a straight line down the center of the cover. The car this came from is a fullsize electra okey doke. then the # off of the end of the door isn't coding like a normal VIN and you need to get us the # from the small plate just above the bottom of the windshield on the drivers side. you'll see it from outside the car.
the 215 / 300 / 340 use 4 bolt valve covers. the 350 is a bored 340 but Buick also swapped the valve order. the 6 bolt valve covers are one of the ways to tell the difference between a 350 and one of the earlier small block engines. .[/QUOTE] Bob..:TU: Being a 455 guy myself.. :laugh: Later,Tony.
Could you guys tell me what quench is. And in a post you said that the 70-71 and 75-76 engines have basically the same compression but 75-76 heads suck for quench. So will changing the heads to earlier year ones have any effect. Is there any other "easy" ways to get compresion up. Id like not to touch the pistons and bottom end since I have next to no little mechanical experiece. Can I make the 76cc heads a lower cc or is that impossible and if so could you explain how. Lastly are there any idenifiable ways of telling a electra year from the body, trim, ect. I can't go back to the car again until I get the heads for the real vin number.
Reply by saturday morning ASAP PLEASE Ok, Im at a swap meet/ car show for fri/sat ,like today, and looking for the 455 heads. Are there any ways to tell a 455 buick head from a SBC or others. Half of the heads arn't labled. Also the only intakes they have are these doulbe carb ones from offenhauser. Are they any good. The is one for 300 and one for 500(come with carbs). Do I want them or not. Any help is appreciated,Stubbe
Hi look at the block not the car look by the bell housing area right on top of the rear of the motor look for these numbers on the engine where are you at in wisconsin i am in plymouth area if you need anything Greg Buick Big Block Casting Numbers, 400, 430, 455 Block Cast # Year Displacement 1231738 70-71 455 1238861 71-72 455 1241735 72-75 455 1241748 72-81 455 1242694 ?-? 455 1318624 67 400 1311624 67-69 400 1311625 67-69 430 1381825 68-69 430 1382201 70 455 1383424 67-69 430 1383434 68-69 430 1383790 68-69 400 1384790 67-69 400 1393444 68-69 400 Intake Manifold Cast # Year Displacement 1231718 70 455 4bbl 1236403 71 455 4bbl 1239925 72-73 455 4bbl 1243020 72-73 455 4bbl 1244302 74 455 2bbl 1245059 72-74 455 4bbl 1245375 72-73 455 4bbl 1247330 75 455 4bbl 1382720 67 400/430 4bbl 1383438 68 400/430 4bbl 1386003 69 400/430 4bbl Exhaust Manifold Cast # Year Displacement 1238094 right 1245433 left 67 400/430 1238094 right 1245443 left 69 400/430 1238094 right 1233451 left 70 455 1238094 right 1233451 left 71-74 455 1238094 right 1246715 left 75 455 1383648 right 1384089 left 68 400/430 Head Cast # Year Displacement 1231109 68-69 430 1231786 69 400/430 1231786 70 455 1237661 71 455 1238148 70-72? 455 1238529 70-76 455 1238530 72 455 Stage 1 1245713 69 400/430 1240144 70-71 455 1240145 71 455 1240146 71 455 1240149 70-71 455 1240150 70 455 1241860 73-74 455 1242001 73-74 455 1242445 70-72 455 1242449 72 455 1246322 75-76 455 1246332 75-76 455 1248922 72-76 455 1250489 75 455 1372963* 67 430 1372985* 67 430 1372986* 67 430 1377979 67 400 1377980* 67 400 1382091 68 400,430 1382720 67 400 1382983* 67-68 430 1382985* 68 430 1382986 68 430 1384720* 68 400,430 1385649 68 400/430 * Big Port
Could you guys tell me what quench is. this'll get ya started: http://chevyhiperformance.com/techarticles/94138/ you said that the 70-71 and 75-76 engines have basically the same compression no, no, no, no, no. i said the 71/74 pistons and the 75/76 pistons have nearly the same effective dish because of the shorter pin height on the 75/76 pistons. the 71/74 pistons have a deeper dish but are closer to the deck at TDC so for compression purposes the two piston styles are pretty close. the 1970 pistons are A ONE YEAR ONLY option and have the smallest dish and best quench that the factory ever offered. the engines in those three different time frames ( 1970, 1971/74 and 1975/76 ) have totally different compression ratios and those CR's are arrived by changes in BOTH head chamber size AND piston dish in all three era's. you can swap a 71/74 head onto a 75/76 block with no other changes and you'll probably bump your CR somewhere between 8.5 or 9.0:1 from the 7.9:1 that you're starting out with. more gains can be made by installing Stage 1 valves and decking the block and heads. you say you don't want to swap pistons but i would think that would be the best option ... just buy the whole engine out of the junk car and that way you'll have lots of spare parts if you run into any problems. if you don't make the seller tear the engine apart you might just get the whole thing for not much more than the price of both heads. Can I make the 76cc heads a lower cc or is that impossible and if so could you explain how. practically any engine / head combo can have it's compression raised. the most common way is to take it to an engine man and have him 'deck' the block and heads ( physically mill metal off of the surface of the block, heads and possibly intake manifold to shrink the space between the crown of the piston at TDC and the combustion chamber in the head ) on his milling machine. of course, this will cost you a little. another way is to get thinner head gaskets then what your engine has on it now. if your 75 engine is using the metal gaskets you can't get any thinner than what you've already got. composite gaskets will all be thicker ( and hence, decrease compression over the factory gasket ). are there any idenifiable ways of telling a electra year from the body, trim, ect. the 6th digit of the VIN is definitive and will be the last digit of the year in the decade the car was made. look up in the thread to the post where i decoded your door #. that's what you're looking for.
Aren't there coolant passage differences between 1972 and 1973 455 heads? Maybe other years as well? It seems I remember that these can be plugged or otherwise easily fixed, but you'd probably want to know that for sure. Nick
My 73 455 heads have 73 stamped on them just above the exaust manifold. also I used small dished pistons and the 73 heads and also had the heads and block decked and my machine shop said I only have 9.1-9.2 comp Many of the buick heads are not the cc's they are supose to be the book said mine are 71 cc and when we checked after tacking 6 thow off them they were 72. and a buddy of mine had the same problem with a set of 70 heads and I also read about the coolant port diferances.
