Big Block Cylinder Heads - Test Results - Big-Block Cylinder Head Test

Comp 10-degree locks	611-16	Summit Racing	22.88
Comp pushrods, 31/48 in.	(see chart)**	Summit Racing	16.99 ea.
Comp 111/432-in. lash caps	621-16	Summit Racing	35.75
Comp spring insert	4779-8	Summit Racing	33.99
Dart adj. guideplates (4)	27001230-4	Summit Racing	33.69
Dart cast valve covers	68000020	Summit Racing	160.95
Edelbrock valve covers	4680	Summit Racing	49.95
Edelbrock RPM Air 2-0	7561	Summit Racing	239.95
Hedman 2-inch headers	66002	Summit Racing	502.69
Fel-Pro head gasket	1037	Summit Racing	42.95
Fel-Pro intake gasket, oval	1210	Summit Racing	22.95
Fel-Pro valve-cover gasket	1635	Summit Racing	42.95
Fel-Pro header gasket	1412	Summit Racing	18.95
ARP head bolts, Brodix	135-3601	Summit Racing	58.95
ARP head bolts, Edelbrock	135-3610	Summit Racing	105.95
ARP head bolts, TFS	235-3707	Summit Racing	179.95
ARP head bolts, Dart	135-3605	Summit Racing	41.95
ARP intake bolts	135-2001	Summit Racing	25.95
Spectre fab. valve covers	5041	Spectre	188.99
Barry Grant 850 carburetor	5563010	Jegs	549.99
Powerhouse Height Mic	101200	Powerhouse	62.95

This is the PN without the CNC chamber Brodix option CNC-chamber price $225.00

The Test
Once we had all the heads assembled and configured, we loaded up the Rat and all the heads and assorted accouterments in the back of our trusty GMC pickup and piled it all up in the dyno cell at Westech. Steve Brul put on his kidney belt, and we set to work thrashing on the Rat.

The procedure for the first test was to bring the engine up to temperature and then go through a series of jetting and timing tests to establish the baseline for the rest of the cylinder heads. It turned out that all the heads used 36 degrees of lead and the same jetting from the Barry Grant Mighty Demon carburetor, which made the thrash a little easier. Once we had a good tune-up, we made three full pulls on each combination from 3,200 to 6,200 rpm, then averaged those runs together to create a power curve for each engine.