tripower 69 vs 67 intake HP differenece

[Michael F.]

what was the real horse power difference between a 68/69 435 and a 67 435 car.

[Joe L.]

Re: tripower 69 vs 67 intake HP differenece

what was the real horse power difference between a 68/69 435 and a 67 435 car.

Michael------

Who knows? However, I expect the difference was not, at all, appreciable. The only differences between the two engines were:

1) the 67 manifold was slightly higher rise; the 68-69 manifolds were reduced slightly in height for hood clearance;

2) for 1967 only California cars were equipped with AIR; for 1968-69 all were equipped with AIR. However, the L-71 was always rated at 435 HP regardless of whether AIR was installed, or not.

[Michael F.]

Re: tripower 69 vs 67 intake HP differenece

Joe, with the shorter intake do you think you would loose any power in upper rpm range??

[Steve B.]

Re: tripower 69 vs 67 intake HP differenece

My guess is that the 67 high rise intake would make about 15 more hp at high rpms than the 69 intake.

[Ralph P.]

Re: tripower 69 vs 67 intake HP differenece

When did the open-chamber heads appear & didn't this make a HP difference?

[Patrick B.]

Re: tripower 69 vs 67 intake HP differenece

The second design L-88 heads which first appeared on the ZL-1 aluminum 427 in January 69 were open chambered, but they were never used on a 427-435. Even the 69 L-89 427 435 continued to use the first design closed chamber aluminum heads after the L-88 had been changed to the open chamber aluminum heads. GM never developed 11:1 compression pistons for the 118 cc open chamber heads, and ,yes, the open chamber heads did increase power over the closed chamber heads in the L-88.

[Mike F.]

Re: tripower 69 vs 67 intake HP differenece

A little off topic, Corvette Fever, Jan. 2000

[Steve B.]

Re: tripower 69 vs 67 intake HP differenece

That's about right for an L72 with side exhaust, the mufflers were very restrictive. An N11 set up would yield much better results.