Hey, I'm new here and have a few questions about the 250 inline 6 for my '66 Chevy C10. I'm building the truck as a daily driver that will also be capable going out to open track days or autocross events. I'm not looking for it to be competitive, just something that handles pretty well and be more fun to drive hard. I'd like to stay with the 250 six since it's what the truck came with from the factory, and also would be unique in the sea of V8's at shows and track events. V8's just don't do it for me.

With that said, what is possible with the 250? I'm more familiar with hi-po VW engines (current one should make 1.5-1.6 hp/ci) but I've not found alot of info on the inline 6 engines. I would like to be able to run in the mid 13's in the 1/4 mile, and I've got a T56 six speed to back the engine.

From what I've found so far I've come up with this as a rough idea of what might work:


1966 block, probably go with 40 over.
Ported original head with bigger valves, lump port kit.
I'd like to run a roller cam and lifters.
Triple Dellorto side drafts (very familiar with these- I run Dellorto downdraft's on my VW)
I can make the intake manifolds from readily available intake/carb flanges.
Forged rods/pistons.
13:1 ish compression on E85- readily available, ~50 cents cheaper than 93, runs much cooler.
Aluminum/steel faced adapter flywheel for the T56, ~20 pounds.


My questions are; what valve sizes should I shoot for, who sells forged pistons (pretty sure I'll need custom pistons though), who's good at porting heads for this level of performance, and who sells roller cams? I guess the big question is; is 350-375 hp even doable for a streetable engine? That would be roughly 1.4 hp/ci, which sounds reasonably achieveable to me, but I'm no expert on Inline 6 engines. I think that the high compression, roller cam, and separate runner intakes (reversion isn't a problem) would help tremendously with low end torque (atleast, it does with VW engines) and would help keep the engine driveable. I'd like it to make power to about 7000 rpm; is the stock crank capable of handling that, or are there other cranks I need to look into? Thanks in advance for any help!

Here's a link to the truck's build thread on 67-72chevytrucks.com

http://67-72chevytrucks.com/vboard/showthread.php?t=474456



1966 Chevy C10 Driver/Pro Touring Build
http://67-72chevytrucks.com/vboard/showthread.php?t=474456