Has anyone used the heads on their otherwise stock motor and seen gains right off the bat? Just curious.

I'm thinking of instead of refinishing my 346's to just buy their heads. Its for very mild 383/4spd Bee with about 9.5:1 compressiona and a XE274 cam with stock exh. manifolds and an old DP4B with the original Holley.

Thanks

I'm wondering how much benefit also. The closed chambers/better ports are definitely going to be a major improvement over the open chamber 70's technology 346's & if your short block isn't finalized you can suppport a higher CR & if it is maybe bring your adv curve in quicker. but they do need to be gone over before your run them out of the box.

It would be cool to see a Magazine Tech article done right at the track, reporting real #'s.

Mopar Action did a comparison to the tech. editors all original 71-383 Cuda convertible several years ago. They took off the old heads and bolted on some Muscle Motors ported heads, but with the stock valves, and gained like 50HP. Later, added a 3310 holley and gained like another 30-40HP over the factory holley. Thats some pretty good gains for a stock, untouched motor with the factory iron intake and exhaust manifolds.

To me, thats a real world comparison when someone like myself can't afford to buy a bunch of high end performance parts and try to make them all work. I want something simple with very little maintenance and fairly stock.

The 440source heads sound awesome beings that they are aluminum and stock appearing. Which is what I'm looking for. I'm wanting to really stomp some local GM butts with a basically stock 383.

i think you will gain around 40-50hp.
plus, you will save around 40-50 pounds.
i have the same heads, but they are still at the machine shop. i will have the dyno results in 3-4 weeks.