...musical exhaust manifolds...

Ok folks - for my mild 360 magnum 'truck' engine...I'm looking at two versions of center dump small block manifolds (for both sides of my engine), and I've narrowed it down to these two: '71 340 p-side, and the later 70's 318/360 truck manifolds.

Both manifolds have similar port sizes, and the same 1-7/8" i.d. exhaust outlet diameter. I was going to use the magnum manifolds that were on the engine, but they aim way way back and frankly make 'getting in there' to access the transmission linkage and such pretty difficult, plus making things pretty toasty and requiring more shields, etc. The magnum manifolds also have the same outlet size of 1-7/8", and with that in mind I'm looking at center dump exhaust manifolds, so back to the 340 or later 318/360 units. The 340's flow good, and I think the 318/360 units probably flow the same, so I doubt there's not much of a flow difference that I would ever notice, and I don't care about gaining/losing 5 hp at 5000 rpm. The later units have more 'cooling fins' and a bigger internal core...but I don't know if that has any bearing.

My brain tells me these (below) both flow about the same, and will flow plenty well enough for my mild 360, again built to be 'done' by 4500 rpm - I'll just be adding gears - not for high rpms - for low rpm grunt work.

So, that said, am I missing something, or would either of these suit me just fine - I'm leaning towards the 340 units...and unless someone convinces me otherwise I'll be picking up a set of the 340 manifolds from a local club buddy tomorrow morning. But if the later truck units would be better...well tell me why.

71 340 -





70's pre-smog small block (318 and 360 I think) -