2.5 or 3 inch exhaust, 351C

[a70stang2nv]

Here's the deal. i have a 351C, edelbrock heads, bored 40, with a 505 lift cam. and all the other goodies but enough to understand. reputation of the cleveland is that it has large valves and back pressure becomes an issue. i'm hoping to find someone with enough experience to know which is better for performance on this engine, 2.5 exhaust or 3. i know alot of ppl may fuss over this issue but i want to get this perfect without wasting the money figuring out which is better. please reply

[Payton King]

dictate header tube size and exhaust size. Hp?

[DocDave]

I am no experts but I would think the 3" would be a better choice. You can always look into different mufflers to create more back pressure if it becomes and issue. I have 3" on my 396 Chevy BB and it loves it.

Then again, I am from the old school mentality where bigger is better, LOL.

[Scotch]

It's still only 351 cubes. 2.5 is plenty.

If you want, run 3 to the muffs and 2.5 out- it'll work great.

~SP~

[rocketman]

Mite as well go 3inch it's not much more than 2.5 and it will make a little more hp.

[deuce_454]

edelbrock heads on a cleveland?? are they winsor style heads?

[6D9]

A mandrel 2.5" with and X pipe is more than enough for your set up. Most feel that after 500hp or so 3" is needed. I went from 3" back down to 2.5" and lost nothing. This is with a 408sbc.

[a70stang2nv]

Originally Posted by deuce_454

edelbrock heads on a cleveland?? are they winsor style heads?

Yes, edelbrock heads, the only company that i could get my hands on a set of heads for this engine.

[fvike]

Originally Posted by a70stang2nv

reputation of the cleveland is that it has large valves and back pressure becomes an issue.

The Cleveland Edelbrock Preformer RPM heads got 2.05 and 1.60 valves.
My 351 Windsor Preformer RPM heads got 2.02 and 1.60 valves.
I'm running 2.5" exhaust and I'm happy with it.

I'd go with 2.5".