L78 vs COPO in 69 ('real' engine horsepower ratings)

[Chuck_Burg]

I would suspect the L72 would have very similar gains from headers as an L78, around 25-30hp. Same 840 heads, cam, intake, carb etc. Very similar engines, more cubes in the L72. Regardless, both engines come alive higher in the rev range with the 143 cam.

I would suspect an L78 with open headers would pull on a stock L72 if both cars had same gearing, weight etc. Both engines need a recurved distributor and bigger jetting to live up to their potential. I have found one medium weight and one light weight spring from the Moroso advance kit bring full centrifugal advance in around 2500rpm. I run my L78 with 37* total timing, 50/50 mixture of sunoco 110 leaded with 91 octane pump. Very nostalgic experience to say the least. Once it gets to about 3500rpm it really starts rippin good. Puts a smile on my face every time!