i have a chance to buy diffrent set of heads for my '73 GP w/400

-- Edited by bigjames on Tuesday 18th of January 2011 10:49:13 PM

-- Edited by bigjames on Tuesday 18th of January 2011 11:08:58 PM

those heads work real well on a 455. do have 6X currently? the 7k3 wiil add some compression ,BUT to take advantage of the flow, You will need to go with a chunkier cam like RAM AIR specs..... that and your gear upgrade will make it jump... opinions will vary...

right now she has 2.11/1.66/96cc

You probably have the 4 x head on your 73. They have a 98 cc chamber and a smaller 1.66 exhaust valve.  You will get a little more compression with the 7K3 heads but the best is the larger 1.77 exhaust valve.  Compression with the 4x head will be 8 to 1 with the 7k3  head 8.2 to 1. with stock pistons.

-- Edited by Beaumont4008 on Tuesday 18th of January 2011 11:47:30 PM

BigJames, so you're the one who bought that nice 73 GP that was on Kijiji a while back, I like the 73 GP. The 1972 7K3 heads are good heads with big valves but they don't have the end bolts holes tapped in for the exhaust manifolds or headers, kind of a pain. A nice set of 6X#4 off a Pontiac 350 or 1978 W72 400 TransAm would work real good on your 400 as well. The 1972 Pontiac 400 7K3 heads were the last year big valve heads with 2.11 intake and 1.77 exhaust valves.

-- Edited by pontorquer on Tuesday 18th of January 2011 11:44:27 PM

yeah i sure did couldnt pass that up!!! thanks for the advice ill try to find a pair of those