I run 8.40's in the 1/8th in my 70. This is a 355 hyd. roller motor spinning over 6000 rpms with Canfield heads. I feel it lay down a bit on the high end, but my question is actually more in the idle and low rpm ranges.
I have a Performer intake. Can a very restrictive intake manifold (for a particular overall engine combo) negatively affect idle quality and low rpm use?
Also, the engine likes to backfire a bit when it's cold. It's seems to pretty much go away when it fully warms up. Could gas be puddling up in the intake or what else could be causing this?
I really feel like the RPM intake would be the best bet, with the Victor Jr. running a close 2nd. My powerband is 3200-6500 rpms.
Has anyone else ran a very poorly matched intake manifold on an engine? What did you find it doing and what happenend when you put the proper one on? Thanks!

------------------
Justin Wray
Fathom Blue 1970 Malibu 1/8th mile best of 8.48 on wore out 26x8.5x14 slicks. 1/4 mile equivalent is 13.10's
Still tuning for 8.30 in the 1/8th or 12.99 in the 1/4. Whichever comes first...

[This message has been edited by 70_FathomBlueMalibu (edited 10-20-2002).]

I would expect the Performer to enhance the idle and low speed characteristics. It could cause the engine to flaten out at the top end. Since the performer has smallish runners, the velocity should stay up and reduce puddling compared to a larger runner manifold. Your probably right, though, about the RPM or Victor Jr. being a better match. As for it laying down at top end, check your fuel system. This is a common symptom of an inadequate fuel supply. If the fuel supply is fine, you could be a bit lean. Sometimes a backfire can indicate a lean condition, try richening up the idle mixture and see what that does.

------------------
Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street (12.08, 113mph, 7.500@92.14 1/8 mile) 355 powered
Pat's Page (Dynamic Compression Ratio Calculator, car specs, Spark plug reading info) (http://cochise.uia.net/pkelley2/)