Motor Options (Need Opinions)

[67_C-30]

Originally Posted by 697498chevy

My '69 307 has 256,00 miles on it . Never been out of the truck . I did take the heads off and had them re-built . May have added a new cam and lifters also . I'd be happy with a good rebuild . No need for high performance . My truck's been original for 40 years and I see no reason to change it . Just my two cents worth . Hope I didn't step on any toes .

No stepping on toes. 307's are great engines, but it is 40 year old technology. Just adding heads like Vortecs will make any old SBC perform better and be more efficient. So much has changed and the CAD designed later model heads acn offer more power, better fuel efficiency, and the ability to run high compression ratios without detonation than any 40 or even 15 year old production heads. The spark plug is moved closer to the center of the chamber and the chamber itself is a high-swirl, fast-burn style chamber than was once only found on race heads. The intake ports are taller and narrower and flow more air on the upper rpm ranges for power while also flowing better in the lower ranges for torque. They are truly better in every way. There's nothing wrong with a stock 307, but if you drove one with a little better cam and Vortecs, I think you wouldn't want to go back.

You can see in first 2 pics that the spark plug is closer to center of the cylinder on the Vortec head. The bottom pic is regular 60's - mid 90's style open combustion chamber on the left and the Vortec chamber on the right.