Inliners International Forums General Discussion Hi Performance Street 292: headers vs. split manifold? Cam?

I have all three exhaust options hanging on my garage wall already, so price is not a factor. As far as will the long tubes fit? I think they will, but I won't know for sure until the engine is installed in the van and I'm wrangling with the headers.

One thing I love about these little 60's Chevy/GMC vans is that they are so light, which makes them fun to hot rod. They have a U design frame, with the unibody construction built onto the top of the 'U'. The suspension is simple 'gasser' style with a straight front axle. These design features all add to the light weight. Its basically an empty box, which simply doesn't weigh that much. I have never had my van on a scale, but according to the GM heritage center, the published curb weight of a '64 chevy van is actually 2850 lbs. The 292 is a larger block, and will add weight so I figure round up to 3000 lbs.

https://www.gmheritagecenter.com/docs/gm...rolet-G-Van.pdf

According to this site: http://www.amotion.com/amcams.html#19641, these are the specs for a 292 stock cam.



188 duration @ .050 and .404" of valve lift seems really small to me, so I am figuring on having this cam re-ground to give me a little more lift and duration. Not too big, but I'd like something a little better then the stock specs since the carbs, intake and exhaust will not be stock anymore.

The cost for the regrind will be the same no matter what duration and lift I want, so the hard part will be determining exactly what specs I want to have it re-ground to.

Santucci's book offers a couple cam suggestions for a 'street' 292. (page 81) These are reportedly what various inline six experts said:

Tom Langdon: #WG1179
duration 194/204 (intake/exhaust)
lift .464/.494
LSA 110

Pat Smith: custom grind
duration 212/218
lift .518"/.530"
LSA 109

Mike Kirby (Sissel Auto)
grind #248H
duration 192/200 (intake/exhaust)
lift .448"/.460"
LSA 112

So.. do these sixes seem to prefer a straight pattern where intake and exhaust duration & lift are equal? or would it be preferred to use a split pattern with a little higher duration and lift on the exhaust side? It seems all the cam recommendations above from Santucci's book are split profiles that have higher duration and lift on the exhaust. Is there any reason to favor the exhaust side? Also, any thoughts on lobe separation angle? I'm wondering what the stock LSA is and if having the cam reground on a little tighter LSA such as 110 or 108 might help overcome this engine's lack of compression. I don't want to go too tight though, since I want to retain my ability to run 86-87 octane regular low-grade unleaded.


What do you guys think?