I have a 1974 Buick Riv stage 1 455 engine, I am wondering what I am going to need to do to bring it close to the 70 455 torque and horsepower rating. It does have the stage 1 heads but I know they are lower torque and power ratings then the 70. I do not want to get crazy with this engine I want to keep it fairly stock possibly a mild cam if needed. The cam that is in the engine they say Buick put in a different cam for the rivs so they had more torque and smoother idle then the A body stage cams. Uncertain how true this is, it was just something I read. Thanks in advance for any advice and input.
What makes a '74 Stage 1 engine different from a plain-Jane '74 455? Pistons, camshaft, carb tuning, ignition tuning. That would be the minimum. You'd also want to upgrade the exhaust system; and add some sort of cold-air induction if the car doesn't have it already. "I" would add an HEI if you don't have one already. Given a choice, I would NOT use the 1970-style pistons. I'd use a modern, slipper-skirt design. And while I normally avoid cheap-junk Chinese connecting rods, with Buick's goofy balance philosophy, different rods might be in order. Alternatively, you could throw a tailpipe turbo on the thing, and keep almost everything else stock. Let the turbo do the work of adding a hundred foot-lbs of torque. You'd have to fabricate -everything- because I'm sure there's no ready-made kit to install on a Riv.
Great reply, thank you, I will be putting it in my skylark/gs, hoping to stay with manifolds, but larger exhaust is not a problem. Also hoping to stay with gs air cleaner and carb will come from quadrajet power. My understanding for the difference is the cam and stage heads.
What's your budget? That will tells us where to stop with the blue-sky scenarios. At a minimum, you need for the compression to come up to at least 9-9.5:1 which would mean pistons, possibly a bore to next oversize. Decking the block will get you a bit more compression. Those heads could use a good, basic porting to smooth things out. Then a decent cam if you want to make it all work. You can go a TA-212 if you want reasonably smooth, nearly stock idle or get as wild as your converter will support.
Figuring the cost will be $5,500-6,500. So planning for that, will visit with builder yet. Convertor, rear gears to be determined yet, visit with builder and we'll decide those items. I dont drive real hard, but would like it if I want/need it and would be nice to run to local track on occasion.
My advice is to CONFIRM that you have what you think you have. I'm very suspicious of a '74 model year vehicle having big-valve heads, or any "special" camshaft. WILD GUESS with no evidence: Stage 1 in '74 meant you got chrome valve covers or a special decal, and perhaps dual exhaust. No special heads, no special cam, no special carb or distributor. Let's hope I'm wrong.
Engine vin matched car, was a stage1 marked car, chrome air cleaner, ZA stage block for Rivera (ZS is A body block) it does have big valves. For Rivs, I found nothing about special carbs or distributor, I did read, some engines did not receive big valve heads, even though they were suppose to.
And a different cam, distributor and carb settings. Early on they were marketed as the "Modified High Performance 455 with Dual Exhaust". My 1972 Centurion is equipped with such.
You can mill the heads .0150. Best bang for buck is getting bowls ported in heads. The machine work under them necks down a lot. A nice port job to remove it and work the turn will net great results w a mild cam. You can use thin head gaskets from cometic. That will help boost compression. Have fun and aim for max torque in that cool sled you have. Some real good advice in this thread I’ve read. Only thing not mentioned is maybe sneak in an efi kit. It would be my next upgrade. Been unlucky w qjets I’ve had built. Maybe I’m missing something but no answers to repair them. Have fun and enjoy.
