I've been waiting a couple years to put my 455 in a machine shop to start on the rebuild.The 64 heads are done with all new valves.I found this set of virgin heads on Ebay that have never been put on a motor. The block is now 30 over. I'm going with TRW pistons and a Comp cam.
I went with the 268.Single pattern grind,454 lift,110 center and it's best between 1500 RPM & 5500 RPM.I believe the best choice for the street.
As for the heads I really lucked out. The guy didn't know what he had. He didn't list them right on Ebay. I was the only one to bid on them. I also was bidding on another set of #64 heads as well. I paid more for the other set that now sits in my garage. They sat in storage in AZ, till this guy got them. When I saw them for the first time I was jumping up and down. You know how the water nipple is rusted out or disformed on most heads. This one was like someone just put it on the head. The guy that worked on my heads also said: that he is sure that those heads never been on a car. The dates on the heads are the same. I never seen a set of NOS heads,but these are as close as I'll ever see.
Great news ! How much did you bore the block, .030" over ? What's in your car now ? Betcha you can't wait to drive it. Why didn't you go with the Eagle forged rods, they came down drastically in price.
I went .030 over There is a big hole in the engine bay of my orange car. Never thought of changing the rods. The original ones were fine. Hope to have it on the road next year.
I went with the 268.Single pattern grind,454 lift,110 center and it's best between 1500 RPM & 5500 RPM.I believe the best choice for the street.
I'm surprised you went with a single pattern cam. Everything I know and have experienced with Pontiac engines indicates that they work better with a dual pattern, with more duration on the exhaust side, that's why Pontiac designed them that way from the factory. Are you going with the HO manifolds or headers?
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Hillar
1970 LS4 (eventually an LS5) Laurentian 2dr hdtp -and a bunch of other muscle cars...
I went with the 268.Single pattern grind,454 lift,110 center and it's best between 1500 RPM & 5500 RPM.I believe the best choice for the street.
I'm surprised you went with a single pattern cam. Everything I know and have experienced with Pontiac engines indicates that they work better with a dual pattern, with more duration on the exhaust side, that's why Pontiac designed them that way from the factory. Are you going with the HO manifolds or headers?
You only need the duel pattern if your under 350HP. I'll be running about 425HP and the single pattern gives you way more top end. The dual was the best at the time these cars came out, but with the advancement in motor tech...... I've been told the single is the way to go. I'm staying with manifolds to get collector plates. I want headers,but then can't get the collectors
Just a good rebuild with crank,bearings,heads,springs,rockers,cam,msd,carb,manifold and exhaust should get me close to that 425hp mark. Also what I've seen on the web and with other 455's ..Like this one at www.proformanceunlimited.com which he is selling with the cast 6X heads.