"At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 454."

[Mark E.]

That's from page 70 in the '70-'72 JG. I don't doubt that fact, but...

Why did Chevrolet engineers specify different distributor boots for small blocks vs big blocks?

Maybe big blocks have less "head room" under the shielding for some reason?

[Terry M.]

Re: "At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 45

That's from page 70 in the '70-'72 JG. I don't doubt that fact, but...

Why did Chevrolet engineers specify different distributor boots for small blocks vs big blocks?

Maybe big blocks have less "head room" under the shielding for some reason?

Some reason is that big lump of iron that is the 454.
Actually I believe it has more to do with the ground details for the braided wire shielding on the Fat Motor.

[Mark E.]

Re: "At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 45

I'm guessing the there's less clearance under the big block shielding, but I don't know.

I'm not sure why the grounding for braided wires would make a difference.

[Paul O.]

Re: "At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 45

Mark

The braiding over the wires are the 454 shielding other then the distributor shield box. The wires then can be routed along any path the works.

[Mark E.]

Re: "At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 45

Mark

The braiding over the wires are the 454 shielding other then the distributor shield box. The wires then can be routed along any path the works.

I understand; I have one of those cars. I don't understand why the braiding or ground wires would affect the need for 90 deg. vs. straight boots.

I'm guessing the engine sits higher, so the shielding box is shorter and has less clearance. But I don't know that.

[Carl N.]

Re: "At the distributor, [spark] plug boots were straight for 350s and 90 deg. for 45

FYI the 1965 L78 has same 90 degree boots as the 427/454 Rats