I have a L69 1985 IROC, with a T5 trans. Motor started smoking when I bought it and put it in the garage 1 year ago. Finally pulled the motor and I bought a almost new Good-wrench 350 crate motor. (Factory 260HP.. doubtful)It has 76cc chambers. I want to replace the cam and heads to get more power. I already have a 3" exhaust on the car, with headers (Edelbrock), and modified HEI system. Also has a Edelbrock manifold and carb.
I was thinking Vortec (64cc) heads and intake would be a good addition with a cam. I realize this isn't the best base motor but its what I have. What would you guys do? Primarily used for street, NO racing.

 

With Vortecs, you'd need different rocker arms as well. If you're going to go that way, seriously consider this kit http://www.sdparts.com/product/SD806...RPMAirGap.aspx - has everything you need to install the heads. But, will require a squarebore carb. This one http://www.sdparts.com/product/SD806...merIntake.aspx is a little more on the mild side, and would allow you to use your current carb and ignition - not a bad idea for the street, just not as good as a double pumper carb for rowing through the gears.

A mild cam like a Comp XE262, or XE268 if you go with the RPM intake, would compliment them well.

On the other hand, your current heads rebuilt, basic port clean-up, new valve springs & retainers, and 1.94" intake valves would raise compression with the dished pistons the Goodwrench has, you could use your current intake, carb, ignition, etc., and would cost you a lot less than going Vortec for very little sacrifice in performance.

 

Motor has about 2000 miles on it, and the heads are bad casting numbers(Smoggers that flow crap). I really want to be about 300 horse at the crank.

 

Sorry, I meant work over your L69 305 heads. I know the crate heads are boat anchors. The L69 heads with the work I talked about, and even the XE262 cam will put you in the 300 crank HP range.

 

What do you think of these heads?

http://store.summitracing.com/partde...5&autoview=sku

These and a cam. These heads might be a little more than a local rebuild, but most rebuilders around here stink. With these I can use the parts I already have.
My intake is a performer (Edelbrock)

 

They'll raise your compression over the crate heads, but not as much as the L69 had.

The Vortecs would produce better power.