hi, any feedback would help, Q. what would be a good cam for a 1970 yh code 455, it will be running #13 gto 400 heads, fully built, approx 11.1 compression,650 d/p holley, weind manifold, i don't mind a rough idle, its only a play thing & will run at the nostalgia drags this year, possibily a comp cams or similar, we don't have as much to choose from as you guys in the us. cheers graham
Before I offer mine - I am wondering if you mean ported #13 heads when you say fully built. If so, then my opinion is that you will like a "single-pattern" cam with between 245 and 250 degrees duration at .050 lift, with between .570 and .590 valve lift. (If you run 1.65 ratio roller rockers - highly recommended - then this will help guide you with your lobe lift determination.)
If you are not going to port the heads, reduce the duration of the intake side by about 12 degrees.
There's a lot more that you will need to consider to get optimum performance - such as a very good ignition set-up.
hi, no the heads are not ported, just reconditioned, with new speed pro stainless valves & new trw valve springs, i dont have roller rockers yet but may go with the standard ratio, i was thinking of a comp cams xtreme energy xe274h, 230/236 degrees duration, is this heading in the wright direction, i am a novice at this game. thanks graham
One satisfied customer here! LOL Of course, I strayed a little from his recommendation, but not by much! When we first started talking new combo we were thinking hydraulic with rhoads lifters....ended up with a bigger Ultradyne solid cam with 255/260 duration @.050 and .611 and .620 lift with HS 1.65 roller rockers that actually measure 1.72. Of course, I am using a set of ported 6X-4 heads.
Moral of the story...listen to Q. He'll set ya straight!