If the "270 cam" is the comp 270H magnum cam it is too big, unless you are going to use 4.56 gears and a 3500-4000 stall race converter and 10:1++ cr . Its a big cam for a 305 and won't work well with a OD trans. not much low rpm torque in this small motor.
Cut the cam choice back. 206 to 216@.050". put some 3.73-4.10 gears in it and a 10" high stall. A 10" "3500 stall converter" will give a real 3000 stall behind a 305. Its just right.
Forget the th700r4. Big waste of money.
Use home ported #4416 305HO heads or L-31 350 vortec heads.
best with .030-.040" shaved off the decks and a thin felpro 1094 gasket for more cr. Use 1.6 intake and 1.5 exhaust rockers.
Its very easy to over cam a 305.
Last edited by F-BIRD'88; 04-28-2011 at 05:45 AM.