Intake & Carb Recommendation for 481" BBC

[Michael Pliska]

Originally Posted by Tim H

Off topic slightly, are you happy with the cyl. heads ? I have been looking at them and the pricing is hard to beat. I ran a 468" RAT with "990" GM heads and a Victor Jr. w/ 850 Bill Mitchell carb and felt that I might have been slighty undercarbed ?

Tim,
So far I am happy with them. The chambers seem to have more of a "point" between the valves than others (the inside point if you think of it as being heart-shaped), which required a little surgery on my pistons. Another friend who used the same heads just dremeled out the combustion chambers, but I figured my pistons were old and the heads were new. In retrospect I would have probably cut on the heads instead. I previously ran iron LS7 heads and a smaller cam (0.660" lift), everything else the same. The older combination ran a best of 6.08 in the 1/8 mile, typically 6.15-6.20. With the head and cam change it is running 5.98-6.00 in the same conditions the old motor ran 6.20 or so.

My only gripe with Patriot was in getting my order straight (I added some parts to the order and they didn't catch them in the first shipment), otherwise they were great to deal with. I got the equivalent of their "0.800 lift" heads, which come with 2.300 intake valves despite the website indicating 2.250. They were willing to work with me on a custom package, as I didn't want the springs (using a near-new set I had), and cutting for my bigger springs. They had great prices on the other components like ARP head bolts & chrome-moly pushrods. Keep in mind that they require longer pushrods and head bolts/studs (which their website should mention but doesn't).

Regards,