toplot

I started this thread on the "newbie" and hope Joe P is on line. Still have the "J" heads, but decided to go with alum and a 30 or 31 cam. the trans in the pickup is a 700 overdrive. would this work for me @ 375 or so HP?? the block is on it's way to the machine shop to check our the Cyls, crank etc, etc, then I'll make a decision on pistons..hopefully it'll go back standard/standard Orig 5.7 has a cracked block and head. no sense in pursuing this as my goal is the 455 '76 BB in the '90 SWB standard cab truck..I believe the orig springs would be OK with the Alum weight reduction ? I'm working on a "entitlement" financial structure so any and all advice is truly appreciated. Cheers

oldcutlass

Your trams is probably fine, as with your front springs.

joe_padavano

Definitely no issue with the springs. I'm less confident in the 700R4 handling 500 ft-lb in a heavy vehicle, but you can always change the trans later, when it blows up.

toplot

Thanks for coming on board Joe. Watched some of your videos, very informative. The best I could find on the curb weight of the '90 SWB Silverado with the auto trans and 5.7 was 3,850# ?. Should be close to the same with the alum head 455 ? I gather this was the first year for the overdrive tranny. I plan a low stall and shift kit also I'll remember to be gentle LOL..

joe_padavano

I'm not sure what videos you are talking about, but I'm always happy to take credit for someone else's accomplishments.

The Silverado front springs won't even notice the difference in engine weight. A stock 455 is probably 100 lbs heavier than an SBC. That difference goes down quickly with the aluminum heads and intake. The 700R4 was first used in the 1982 model year. In 1990, GM renamed it to the 4L60 (not to be confused with the 4L60E), but it is the same trans as the 700R4.

lemoldsnut

Something to point out about the 700r4 is that they came with only the Chevrolet bolt pattern not the BOP bolt pattern. So an adapter would be needed. I had a full sized blazer with this set up it was 4x4 and had a very well built 455 >060 over and on and on. It worked very well. Wiring switches to the other side for starter as Chevrolet starters are on the right side and and Olds is on the left. But that to is easy as there is plenty of wiring.

The 700r4 in the one I owned was built up and worked great

70cutty

I'm sorry but I have to ask the question WHY? Why go through all the trouble with converting it to olds when chevy motors are dime a dozen and they fit right in with no mods or adapters.

oldsmobiledave

For all of us who own & love Olds powered Chevy/GMC pick up trucks the answer is BECAUSE WE CAN.

70cutty

Don't get me wrong I love Olds too, but I love saving money and doing what makes sense much more.

oldsmobiledave

My GMC was Olds powered. Olds diesel that is. The transition to 455 gas engine was easy.


If doing what made sense took priority there would be far fewer hot rods.

jcdynamic88

If doing what made sense took priority there would be far fewer hot rods.[/QUOTE]

amen

70cutty

if olds was such a great engine with limitless aftermarket parts, there would be a lot more hot rods runing it. With all due respect to OP, we are talking about a 1990 Silverado, to convert it to olds will cost a whole lot more than getting a decent BBC and sticking it in, or if you really wanna get fancy go LS. Encouraging OP to throw money away into bottomless pit aka BBO is plain wrong. If he was doing an Olds and wanted to put Chevy in it, I would be against it. If you guys want to help than point him in a most cost effective way to get his truck back on the road. JMO.

toplot good luck with your build. Your weak points will be cooling, transmission and rear end.

toplot

"Cutty"..Thank you and I appreciate your concern, however my greatest weakness will be my back pocket LOL. I'm aware this is not the most economical route, but it's what I want to do, I've told all of my friends what I'm going to do. I'll not disappoint or embarrass myself. It can be done, others have done it and I'm going to do it. I'm not in a hurry to get it done, I've always had nice Olds when I was younger, and being past 70 I'd better get a move on. Where we live a pickup is the only practical build option @7,400' in the mountains of Wyo. I've caught enough hell already for building a 2wd up here! There are plenty of rear end options, perhaps a new radiator with elec assist?. The trans I'm going to have to make work for a while but I have the orig builder 400 that was in the wagon. One thing at a time that's for sure. First is getting the mach shop report on the block, crank (yea I know its cast) etc before any more decisions need to be made. Once again, Thanx for your input.

toplot

Can you help me with the correct motor mounts, headers etc to make this happen ?? any help would be great! adapter OK I've got that covered, Alum heads, rollers on the way..What else ??..Robert

64Rocket

IMO, putting a chubby in an Buick,Olds, Pontiac, is not cost effective also, but they still do it. For me chubby is the weak link.

Gene

rad

Ive got a 66 chevy truck im starting on for a 455 conversion i could build a 496 chevy pretty easily but in my situation my olds engine is complete with brackets and all, the bbc isn't complete so with my deal the olds is cheaper, i put a 455 in a mid 70s 4 door nova back in the early 90s with ported heads headers turbo 400 etc. There wasnt much that would come close to it in a street race, you can build cookie cutter chevy engines all day long and probably cheaper but why have a vehicle like the guy down the street what your doing is a pretty common conversion dont let anyone discourage you

toplot

Anyone help me here? I've got 77CC alum heads and 10.1 (in stock heads) dish silv-o-lite pistons. What will this combo yield in Comp ratio??? Also still needing help on MMs and headers for this app. Adapter for the 700R4 to Olds no problem. What needs to be done to the tranny to help it live behind the 455? Thanks as always