My goal is to build a highway cruiser and i have already sacrificed a lot of performance items to do so. No big carb, no high compression pop-ups, 2.73 open rear, small cam.

I thought i was safe with a 8.75:1 compression 454, but now i realize that GM's 8.75:1 HO 454 crates recomends high octane.

Whats the limit??

-Ryan

------------------
1970 Malibu 454 (http://www.chevelles.com/showroom/malibdreamer.jpg)
Frame up restification in progress (http://www.chevelles.com/showroom/MalibuDreamerframework.jpg)

My 73 454 with flat tops and open chambers is a nice cruiser with plenty of ooomph to get my 66 movin'. I put on a single plane(torkerII), and headers. It has a little more cam than you'd probably like, but I can cruise on the highway with no overdrive at about a quarter tank an hour.
Impressive, huh?

It's pretty low compression. Maybe 8:1. It works fine on 87 or 89 octane. Part of the fuel consumption problem is currently being sorted out with a carb rebuild and tune with help from Dean and Mike Parris.