1981 Stock Engine Rebuild
Thread Starter
4th Gear
Joined: Sep 2018
Posts: 4
Likes: 0
1981 Stock Engine Rebuild
I have a 1981 c3 with an all original drivetrain right down to the pesky emissions system with approximately 70k miles. I'm looking to rebuild the engine and eliminate the emissions junk and add some power. I'd like to make somewhere in the ballpark of 350-375 horsepower but want to retain good driveability (smooth idle, good vacuum etc.). I'm just wondering if anyone out there has done a build like this and what you used (heads, cam, etc) and if it's cost effective or better to just go with a crate engine. Any input would be greatly appreciated.
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
I have a 81 and i went with a crate motor but if you use stock motor I would rebuild lower end since you'll have it out. Then some new heads, cam, new intake, dist and carb. Only difference is stock block is 2 bolt mains, crate motor 4 bolt mains but if your driving around town, no difference. If you want more power go 4 bolt mains 383 stroker.
Eliminate the computer
Eliminate the computer
Racer
Joined: May 2018
Posts: 297
Likes: 43
if your keeping the heads and intake with carb you can eliminate the smog pump but you will need a spacer on the water pump bolt unless you leave the mounting bracket for the smog pump on, you will also have to plug the exaust tubes from the manifold. I used a bolt and added gimmicky chrome open element breathers on those tubes, looks better then just two bolts sticking up and was more appealing to me because I can always add the smog stuff back if emissions testing is ever required. I would leave the charcoal canister and re route the vac lines to the temperature sensor fpr the smog pump. this will eliminate the emissions and allow you to replace them if you ever need or want to, but if your not keeping the stock intake then the above will not apply
Thread Starter
4th Gear
Joined: Sep 2018
Posts: 4
Likes: 0
The plan is to eliminate all emissions and install headers and dual exhaust, I don't really see any point in leaving that stuff on. I'm just looking to see if the engine is worth salvaging to get the horsepower I want (about 350 and yes I know those garbage factory heads have to go) or to just send it sailing and buy a crate engine.
