As much as I'm a huge fan of Pontiacs, the engine tech is really long in the tooth and it's hard to justify the hippo-sized weight with the options out there.
My 67 LeMans convertible is getting an LS6-headed LQ9 and a T56. Easy 500+ hp with the right wallet.
If I were keeping it "in the family" and old school, hands down, Caddy 500. Only about 30 lbs heavier than an SBC, way lighter than a Pontiac, and 500 cubes means super easy to get whopper power without having to open the big wallet for all the other stuff like gears, converter, etc. I had one making north of 400 hp in a 66 Bonneville and I actually opted for a lower-than-stock stall with a Diesel converter in the TH400. Traction was still a problem with 3.08s.
Grab a later 500 (lower compression), pocket port the intake, fully port the exhaust, Edelbrock intake, Qjet. BBC headers fit if you cut the flanges off and weld on caddy flanges. Mild cam in the 204/214 duration area. 450 hp and well over 500 ft-lb, and can take a stock converter and highway gears and 87 octane.
My 67 LeMans convertible is getting an LS6-headed LQ9 and a T56. Easy 500+ hp with the right wallet.
If I were keeping it "in the family" and old school, hands down, Caddy 500. Only about 30 lbs heavier than an SBC, way lighter than a Pontiac, and 500 cubes means super easy to get whopper power without having to open the big wallet for all the other stuff like gears, converter, etc. I had one making north of 400 hp in a 66 Bonneville and I actually opted for a lower-than-stock stall with a Diesel converter in the TH400. Traction was still a problem with 3.08s.
Grab a later 500 (lower compression), pocket port the intake, fully port the exhaust, Edelbrock intake, Qjet. BBC headers fit if you cut the flanges off and weld on caddy flanges. Mild cam in the 204/214 duration area. 450 hp and well over 500 ft-lb, and can take a stock converter and highway gears and 87 octane.
