Hmm,the performance gains for the 340 manifolds
don't seem so great,for the money I see them sell for.:(
16 hp increase using the TTI headers,I wonder how much the
"new 63-66 early a-body" headers will be worth.... Hmm.
{Also :( How much will they cost too.}
http://moparmusclemagazine.com/techarticles/155_0307_exhaust/
Exhaust Blowout on a Mopar 300hp Crate
Running the numbers on a mild 360
For our baseline test, we fitted the 360 with the lowest of exhaust low, a set of stock small-passage 318 iron exhaust manifolds. Bolted to the manifolds was a set of 21/4-inch head pipe extensions 24 inches long. So equipped, the 360 put out a respect- able
311 hp at 4,600 rpm and 403 lb-ft of torque.
We moved up a notch from the early 318 iron manifolds to late 360 iron log-style manifolds. The 360 manifolds are nothing to look at, but the internal passages and outlet are significantly larger than those of the 318 pieces. Power was up a little, moving to
314 hp and 407.1 lb-ft
'
Our final test of factory iron was a set of rare and expensive early 340 high-performance manifolds. With the 340 exhaust, the 360 inched up to
315 hp and 409.1 lb-ft of torque, which represented very little gain on this engine.
The layout of TTI's headers is unique, with none of the low-hanging tubes of the other designs and ample clearance for the plug wires up top. Past experience has shown they have excellent chassis fit. Power output with the tti's was the best of all the systems we tested, clearing
327 hp and producing a healthy 425.5 lb-ft of torque.