Took the 350 out of the '71 vette(non-original) to put in the '76. The reason is that the original motor out of the '76 is in pieces due to a bad cam bearing. Since I have a complete running motor out of a car that needs a body off resto anyway, I figured I would go ahead and put the motor from it into the '76 and drive it around and try to sell it(along with the numbers matching block).

So, taking the top end off the 350 I found that the block is a 1983 350 with 165HP However the heads are:

"3973487X. The regular casting was found on the 1971-1972 350 LT-1 engines, had 1.94/1.50" valves, 76CC combustion chambers, DO have accessory holes, intake port volume should be 161CC's, exhaust port volume should be 65CC's. The 487X had 2.02/1.60" valves."

I have the "487X" heads which supposedly have a increase of 10CC in the intake runners. I am not sure if they are 1.94/1.5 or not yet.

The motor has good power, just not sure what has been done to it. Don't want to spend a lot of money to put it into a car that will be sold eventually anyway..however do want it to be fun to drive for me and prospective buyers.

So, obviously I am going to have the heads cleaned and checked out, probably a valve job since the old ones are pretty rough.

So, gimme some ideas on what you think a good cam choice would be for those heads and the Eldebrock Performer Manifold?

I want decent power and good sound. 350HP would be good if possible.

1983 block?
Oh, I get it. Not a 'vette block. Sorry, can't help with the build.

lol...think it came out of a truck...good catch though

You can't base the hp rating off the 1983 block if it has LT1 heads on it. I'll have to try to find info on those heads / flow / hp later. Do you have any idea what cam is in there now? What about the pistons/compression? Was it sufficient for the 71? If so, why change it? Maybe just clean up the heads and slap the top end back together.

Matthew

Matlak is right. You can't base anything off the 1983 block since it appears it has been into before. All pre 1986 SBC's are pretty much interchangeable. The block dosen't matter if it's a 1965 or 1985.

Current HP and potential HP after a cam change all depend on what pistons are in it (ie compression ratio). Honestly it will be difficult to make 350HP with a low compression unknown short block, a set of big chamber smog heads and nothing else but a cam and Performer intake.

An orginal 71 LT1 would have had 4 bolt main block, a forged steel crank and forged flat top (with a single trough style valve relif) pistons.

487X casting heads came on other engines besides the 1971 LT1. 71-72 Corvette 270HP base engine and and the 4bbl full size car engines when the heads are comfigured with pressed rocker studs and 1.94/1.50 valves. If they are orginal 71 LT1 heads they will be machined for screw in rocker studs w/guideplates and 2.02/1.60 valves.
Will

Right on....I did some more research on the heads and people say that they were pretty good flowing heads even with the large chambers....

But your both right, the motor pulled the '71 pretty decent and like I said I didn't want to put much more money in it than I needed to. I have no idea what is IN the motor. To upgrade cams to say the Compcams Magnum 280H I would have to spend atleast $400 for the kit with springs on top of getting the heads re-valved and such.

I think I will just use it as it sits and plan a Big Block buildup later for the '71. Thanks guys