Thread: 350 rebuild questions

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Probably you are referring to a 350 H.P. 350 that was offered in Corvettes in the mid-70s and crate engines that simulate that engine. There was a lower H.P. Corvette 350 offered at the same time rated at only 300 H.P. People here have reminded me that sometime around 1970 the way in which GM rated the H.P. changed so as to lower the values by about 50 H.P. Today you can buy a Goodwrench 350 "Universal 350" for about $1500 but it turns out that it is only rated at about 220 H.P. Dyno tests have shown that with (long) 1 5/8" headers, Edelbrock Performer intake and Comp Cam 268 cam this engine yields about 325 H.P., but once you change the cam you have lost the warranty from GM. With only the bolt on Performer and headers you can expect about 260 H.P. Check out:

http://www.73-87.com/chp/gm350.htm

There are a lot of things I am learning while building a '29 roadster from scratch using store bought parts, but I think I really researched the available 350 offerings and I ended up having a local guy assemble a cheap $280 rebuild kit with cast pistons and another $100 for new rods and rebuilt 882 heads with all parts and labor adding up to about $1300 but then I wanted some porting of the heads and was charged $200 to just port the exhaust ports, not the intakes, so I stopped there and added another $98 for roller-tipped 1.6 rockers from Speedway; the rebuild included a mild Crane cam very close to the original 300 H.P. Corvette cam. That was the limit to my budget, but I am stuck with the cast pistons which rule out future supercharging. Note that if you are going to spend $300 to rebuild old heads, you could get better aftermarket heads for about $500-600 or Vortec Heads for about $400 but you would need a different manifold for the Vortec heads. Since the heads were resurfaced, the new chambers were reduced to 75 cc from 76 cc and with the flat top pistons I figure I ended up with something close to 9:1 C.R. so I will still be able to use 87 octane gas. If I did it again, I would have saved longer and bought a 383 kit from PAW but I am on a budget and the shipping of the PAW kit to the East Coast was almost as much as the 350 I had built and anyway putting a 260 H.P. engine in a Model-A chassis originally motivated by a 42 H.P. engine is enough performance for me at my age.

Don Shillady
Retired Scientist/teen rodder