Best headand cam combo for 421 SBC

[Marv D]

For 420+ normally aspirated inches you want at least a 220cc head. Problem is most will require a offset rocker. Starts eating into the budget pretty heavy.

Heads $1400,
Crower offset shaft rocker around $900
custom cam to get the most lift you can get in the combination you have.. around $300


For getting exactly what you pay for, AFR is a phonenominal option. I do believe they are the ONLY one to guarentee flow to be within 1% of advertised. I've had 4 sets, 2 saw the flow bench and were within 5cfm ,, and one was MORE than advertised. The 220 eliminator would serve you well for the big inch sbc running under 6500 (which will be your limit with a hydraulic roller anyways) . Be cautious of getting just any large runner sbc head. Some have absolutely TERRIBLE port volocity and would mot make a street friendly motor. The right head for the right job

Wanting to be more serious, ,, well it's only money

[Evanz67]

Originally Posted by Marv D

For 420+ normally aspirated inches you want at least a 220cc head. Problem is most will require a offset rocker. Starts eating into the budget pretty heavy.

Heads $1400,
Crower offset shaft rocker around $900
custom cam to get the most lift you can get in the combination you have.. around $300


For getting exactly what you pay for, AFR is a phonenominal option. I do believe they are the ONLY one to guarentee flow to be within 1% of advertised. I've had 4 sets, 2 saw the flow bench and were within 5cfm ,, and one was MORE than advertised. The 220 eliminator would serve you well for the big inch sbc running under 6500 (which will be your limit with a hydraulic roller anyways) . Be cautious of getting just any large runner sbc head. Some have absolutely TERRIBLE port volocity and would mot make a street friendly motor. The right head for the right job

Wanting to be more serious, ,, well it's only money

Thanks for the info. In your opinion then Marv do you think HYD roller is the best choice or would something else be better suited. The truck will probably only be driven about 300 to 500 miles a year at most.And is 550HP attainable out of something like this.Thanks again.

[Super73]

Originally Posted by Marv D

big inch sbc running under 6500 (which will be your limit with a hydraulic roller anyways) .

Marv,

Do you know the diameter of a stock SBC lifter? I'm wondering how close they are to LS lifters. I'd be curious to know also how the oil galleys look in comparision. If one could find a way to use a Hyd LS lifter, the CTS-V or LS7 lifter has been shown to work all they way up to 8,200rpm in the 24 hour CTS-V races. Obviously you need to be creative for oil control.

I know we have discussed Hyd lifters and their limints before, but I know from experience that the LS lifter works past 6,500. Even a bone stock LS1 lifter from 98-02. I had a set in my old motor spinning to 7,400. Even made a few dyno pulls to 7,800 with it.