Getting very frustrated trying to figure out what is the correct shroud for me Skylark. Hope you can help. I have a 1972 Skylark that i have converted from a 350 to a 1970 Stage 1 455. I have 2 shrouds and both of them do not fit. I thought the last one I bought was correct but the hole seems to be offset. It looks like i need one with a hole centered in the middle of the shroud. The fan is rubbing on the shroud. Does the rad support have to be changed or does it fit both? Please let me know asap. Does anyone have the correct shroud? Thanks in advance. Leo
Radiator support does not change as these are the same for 70 -2. ( maybe some minor differences but they are the same size, shape, etc.) The 70 455 shroud was a one year only I believe. They make repros & it has been discussed on the board a great deal. Search for shroud and read some of the posts. I've heard some of the big cars shrouds will work, but others on the board know a lot about it than I. I believe a 1970 Electra shroud will work on the 1970 GS. A board member , Kimson has one of these for sale.
"I have a 1972 Skylark that i have converted from a 350 to a 1970 Stage 1 455." From the above I can't tell if you did the motor to 70 Stage 1 specs or if you used a 70 motor, but the information below is the skinny. You have to use the same year shroud that matches the pulleys/brackets/water pump/fan assembly you are using. The pulleys have two styles, 69-70 & 71-72, so if you have a 70 pulley set then you need a 70 shroud. And one other thing, You also cannot mix/match the radiator insulators. They have different offsets built into the rubber. If you try to use the wrong year insulators you end up with either one of the two situations; 1. You have to physically jam in the shroud to make it fit, and it will rub against the radiator core (which is a problem waiting to happen) or 2. The shroud will have a gap between it and the rad, where air can be sucked around the edges and lessens the rad cooling capacity. I wrote an article about this for the BPG that explained everything with part numbers/pictures etc. Maybe someone can get you a copy, or you can become a member and get the info off their site. Duane
And some people have been known to try and pass off a modified 72 shroud for a 71 shroud in a concours show....
Duane I do have a 1970 pulley set up. It all came with the engine when i got it.Also have a 1970 shroud according to the pictures on the BFG dite. When i put the shroud on the tabs for the rad cradle, it pushes it over towards the driver's side and rubs on the fan. I have not changed the rad cushions. It is the same rad I had recored. Totally confused!!!
If you have a 72 Buick then you are trying to use the 71-72 style radiator cushions for a 70 set up. These position the radiator towards the engine and could be creating a binding problem with the fan shroud. (The 70 rad cushions position the radiator away from the engine.) You should use the 70 cushions for a 70 set-up. The fan shrouds are made to have a little side-side adjustment, but if the shroud is being jambed in there, it won't let you move it at all. Two other questions, are you using the right style 70 fan blades for a 70 shroud, and is the shroud a repro or an original? The reason I ask is 71-72 style fan blades are different, and you may have to play with the holes on a repro shroud to get that extra little bit of clearance. Another thing could be the rad top cover plate. Each year 70,71,72 is different but I thought the fan shroud mounting holes were all in the same place. Maybe they were shifted for the 71-72 models, I never bothered to check that. Sounds to me like you are still mixing & matching parts, and if that's the case you will continue to have problems. This is exactly the reason I wrote the article and listed all the part numbers, because I went through this same thing years ago. Duane
Thanks Duane. Will look into that too. From what i can tell it looks like i need the 1238973 shroud which should fit the 72 455. The 7 blade clutch fan was on the original 350 that was in the car. Never thought this would be the toughest part of doing a complete body off resto!!!! Leo
Leo, If you are using a 70 455 set up then the shroud you need is a 70 BB shroud, part #1233000. I still think you are mixing/matching parts so I will make it a lot easier for you. Listed below are the various part numbers for the different set-ups. Duane 1970 Components Water Pump, 350 all, short shaft, # 1374877 Water Pump, 455 non-AC/Std. Cooling, short shaft, # 1372812 Water Pump, 455 AC/H.D. Cooling, short shaft, # 1386961 Radiator Core Support # 1231398 (Number stamped into the upper bar) Top Cover, early style # 1232819 (Plastic with Steel end caps) Top Cover, late style # 1234369 (All Steel) Fan Shroud, Small Block # 1232996 Fan Shroud, Big Block # 1233000 Rubber Insulators # 1387423 (LT, RB) (Cast into part) Rubber Insulators # 1387422 (LB, RT) (Cast into part) 1971 Components Water Pump, 350 all, long shaft, # 1235958 Water Pump, 455 non-AC/Std. Cooling, long shaft, # 1380118 Water Pump, 455 AC/H.D. Cooling, long shaft, # 1233531 Radiator Core Support # 1237210 (Number stamped into the upper bar) Top Cover # 1237506 (All Steel) Fan Shroud, Small Block # 1234555 Fan Shroud, Big Block # 1234484 Rubber Insulators # 1236777 (LT, RB) (Cast into part) Rubber Insulators # 1236778 (LB, RT) (Cast into part) 1972 Components Water Pump, 350 all, long shaft, # 1235958 Water Pump, 455 non-AC/Std. Cooling, long shaft, # 1380118 Water Pump, 455 AC/H.D. Cooling, long shaft, # 1233531 Radiator Core Support # 1237210 (Number stamped into the upper bar) Top Cover # 1240323 (All Steel) Fan Shroud, Small Block # 1238972 Fan Shroud, Big Block # 1238973 Rubber Insulators # 1236777 (LT, RB) (Cast into part) Rubber Insulators # 1236778 (LB, RT) (Cast into part) Abbreviations LT= left top RT=right top LB= left bottom RT=right bottom
Leo, Post some pics and it will help us determine what you have. Take pics of the top of radiator cover and where the fan shroud tabs mount to it, the fan and shroud opening, and the water pump pulley/fan. The fan shroud opening is 22" in diameter on my 72 455 Stage 1 if that helps.
Thanks for all your help guys. Will try to take some pics. Duane I'm sure the info you sent will be very helpful. Anyone have a shroud? Looks like I have 2 very good 350 shrouds I will be selling. Leo
Leo i have a 71-72 big block GS fan shroud part #1238973 can get pics if you are interested $225 shipped
Guys Here are some pics of the 2 fan shrouds i have that I am trying to mount on my 72 Skylark with the 1970 455 engine. The top plate i have is off the original 350 from the car. Any thoughts? Thanks Leo
