Will AFR 165s work with flat tops and 230 duration and .512 lift cam?


Active Member
Jun 24, 2004
Frankfort, Ky
Ok final question. Will AFRs Probably work or Probably not work with flat tops and a cam with 230 duration and .512 lift? If not I'm going to go with a set of D00E 351 heads for now and wait until I build my roller motor to go with better heads.
  • Sponsors (?)

It depends on where the duration is and where the lift is and anybody that tells you otherwise is full of it; Consider lobe separation, lift, lobe center, angle and dangle of the curve, and of upmost importance the lube of the jube!!!! Get a hot cam and go for it.
Would all depend on the size of the valve reliefs you have now, the size vavle you are going to, and the timing. Duration, and lift are not as important as WHEN they open and close. I bent many vavles on a stock motor with heads ( intake 2.02 intake) and it only had .512 lift.
Well, I think the stockers are 1.79, and the new intakes are 1.94. Not as big as the 2.02, but still larger than the stock reliefs and valves. I would just suggest buy the valve cutter that slips in the head and cut them yourself. Not perfect of ideal, but since you have the heads off anyways. And if you do, then you can get the 185's since you have to cut into the piston anyway. Hard to tell if it will fit, without claying anyways. I guess you have to balance whether you want to chance buying the 165's, and them not fitting with that cam, and having to cut the bigger reliefs, OR get the 185's and do it anyways, and get the heads you seem to want to run anyways. BOY what a run-on.
I ran my 1.94 valved Canfields with a B303 roller( 224 degrees @ .050 and .510 lift) with 1.7 rockers, milled the heads .060, and never encounted a problem. And this was with an el-cheapo $340 shortblock that had flat topped Silvolite pistons. Go for the AFR's and that cam, I'm 99.9% sure you won't have a problem.