360 headers

[65mopar273]

with the troble you run into running headers is there a stock manifold that i can run on a stock 360 with a aftermarket cam how much hp would i be loseing .:cheers:

 

[1wild&crazyguy]

what car, what manifolds ?

14-20 hp average, but average for what? lol

 

[moper]

I've had stock 68-71 340 HP manifolds on the early As before. The early A manifolds are restrictive as hell but that's what I'm going to run on mine for simplicity and look. The steering shaft on teh driver's side and the torsion bar on the pass side are what really screw up the fit using later A stuff.

Edit: In terms of power los... Probably close to 10% on a build. A mild (350hp) 360 will give up about 35hp. A higher output larger engine, say a 450hp 410" will give up closer to 50. You can also lower that figure with careful cam selection if you know you don't have any scavenging.

 

[65mopar273]

Ihave a 99-360 mangum i going to use in my 65 valaint an aftermarket intake and cam with the stock manifolds would that cut down on hp?:read2:

 

[1wild&crazyguy]

the cam makes all the diff.

the magazine testing shows around 14-20hp using a 300hp 360 crate motor.

thats what I mean when I say 'average for what?'

 

[pettybludart]

Ihave a 99-360 mangum i going to use in my 65 valaint an aftermarket intake and cam with the stock manifolds would that cut down on hp?:read2:

Yes it will choke it with the (273)stock exhaust manifolds.

 

[65mopar273]

What if i were to use the 360 manifolds or if its best to use headers what size and type would be the best to use in my 65 valaint with the 360?