I thought this was pretty interesting. Hot Rod (not Car Craft...) magazine did an article this month on hotrodding the straight six Chevy. The rods and pistons are quite a bit different, I think I read they use certain V8 rods and pistons, and then bore the cylinders to match. The heads are ported pretty heavily, or you can get the modernized aluminum head.
These guys were pulling 1 hp/ci or more. With the available Clifford intake and a Holley carb, these motors made big power to about 4800 and then fell on their face. However, either fuel injection, or a custom manifold boosted the rpm ceiling to almost 6000 rpm and boosted power on these motors to about 1.24 hp/ci. These things were making over 300 hp!
Although a V8 still has more potential than that, these guys aren't done yet. There is a turbocharged I6 in the works next.
Are we gonna see 400+ horse Inline sixes in these trucks now? Wow.
Check out the article, it's really interesting.
