[68stang73]

hey guys i have a 68 mustang with a c4 trans. building a 351w .30 over. the pistons are H336p .30 in a 79 block. my head guy said they were 8.1 and online says they are 9.47 with a 60cc head. im using 66 289 heads 60cc ported on exhaust hogged out to 1.94 and 1.6 with the head shaved i think he said it is a 30cc now. well who is right on compression. in his thought with 8.1 and my heads i am now about 9.7. i think im higher. any thoughts? also he used the duel spring by comp cams 1.437 he said they are good to about 570 lift...i cant find that info is he correct? any ways im looking fo a great cam to stuff in it. i love the old nasty nestalga sound but want fast acceleration and upper hp at higher rpms. want the most out of it in a hydrolic cam. also should i remove inner spring to break in a cam? im thinking of running a 2000 stall with 3.5 in the rear...

[KLWorra]

What is the CC of the piston? How much in the hole is the piston? What thickness head gasket you going with?

I am confused, you say the CC of the head is 60 and then you say it is shaved and now about 30CC. That is a MAJOR difference. You will need to know what the actual CC is, not guess.

You should also flow the heads to determine what they will produce so that you can pick the right cam/intake/carb combo for your application. Too big a cam for poor flowing heads in a larger cubic inch engine will be a total pig. No fun to drive.

IMHO. For a high rev HP 351 motor you will need MUCH bigger heads, higher torque conv, 3.73 to 4.11 gears.

When your ready with actual compression ratio, call a custom cam grinder or Comp Cams, they are great at giving you good information and asking the right questions to ensure you get what you expect out of a combo.

[68stang73]

i couldnt tel you the cc of the piston as i bought the shortblock assembled. the builder past away. all i have is the numbers on the piston the ones i mentioned earlier and thes on the bottom 127-03-02-0. and the heads are 30cc. he milled 30 off. i was thinking thumper cam but not sure now. im asuming to go with somewhere around 500 to 523 lift cam?????