Danp76

I'm in the process of restoring a 71 olds convertilbe with a 350 engine. I would like to freshen up the engine, and get a little more power from it as well. I plan on rebuilding the heads, any suggestions on what I should do to the heads? I don't need something very powerful, just a nice driver. Maybe 350hp range? Sugestions? Thanks guys!

captjim

To get an honest 350 HP you are going to need to change the pistons to increase compression and upgrade the cam along with significant head work.

That said, you really don't need 350 HP. The biggest issue is that 71 and 72 350s have a BIG dish in the piston. This makes getting decent coompression tough. 8.5 to 1 is going to be about it. That with a good valve job, a little port work, decent cam (somewhere in the 210 @ .050 and .480 lift range) and it can be a fun runner. A gear change will also perk it up.

Danp76

I don't mind installing new pistons, especially if the old ones are tired. I want a fun runner, it doesn't have to be an extreme power house. I'm more or less looking for a reliable fun car with some pep. I don't want a choppy or loopy idle, I think it would eventually get annoying.

coppercutlass

even with new pistons if you go with flat tops you end up with roughly over 9.5 to one compression depending on the deck height and cc of the heads. That is still good on pump gas. I ran a 9 to 1 combo with a very mild 260h comp cams stock re freshed heads all stock valve train parts exc. cam, edelbrock perfomer intake, eddy 600 cfm carb, headers, .had a near stock idle ran high 13's through the exhaust of course with all the proper runnining equiptment like torque converter and rear gear. This combination had near stock driving characteristics it idled great no big lope not too agressive to drive long distances. Im not sure on how much hp it made but it it ran at it's best a 13.86 .

DoubleV

Just curious, but what was your MPH?

coppercutlass

98 mph.

Danp76

I need a "recipe" to follow for the engine build. From piston manufacturer suggestions, to what if any head work should be done to the number "7" heads. Do I rebuild the heads stock and add flat top pistons? Keep the stock cam configuration? I don't want a choppy or loopy idle. Do I keep the stock intake manifold and rebuild the original carburetor or what do you recommend? Thank you!

my71olds

Coppercutlass what speed shop or machine shop did you use? I am not far from you and looking for a speed shop to consult with to rebuild my 350 from a 71 olds cutlass. Thanks

coppercutlass

I built my own engine i farmed the machining to opel engineering in streamwood il. I picked all my parts and planned the build my self.

brownbomber77

I'll always use my own machinist in Belvedere, IL. He has access to al lthe torque plates n' such for Oldsmobile (and anything else). I do build my own engines, but he is more than capable of doing the job, of course. A little further than Elgin, but just giving options.