5.7 in a 64 valiant
This should bring a few memories back to the old timers who had/ran '54 & up fords & mercs ,& F100's with the Y-blocks 272/292/312ci V8 converting stock single system manifolds over to duals ( when they were all the rage back then)
As an interesting aside Carcraft put a psi meter on the stock single downpipe system: a tapping after each manifold & @ 100mph got stock w single OEM muffler - 2.4 inches left, 1.7 inches right. Changed to duals with pair stock OEM mufflers & std manifolds: 0.4" inches BOTH sides NO other changes...the best they'd ever seen with a basically stock setup @ 100mph 4,000rpm (police interceptors of the time were fitted STK w duals,160hp)...Point of note dad telling me as a kid the 1st Y-block they got in at work from Ford, they had to remove that HOT exh crossover pipe that ran across in front of the engine & like the young racers they were thought they'd take it for a strop around the back streets late at night & this thing just CAME ALIVE with open manifolds, & a tram just happened along out of the blue, req evasive throttle & lit up BOTH rear skins leaving black lines for 1/2 a block for weeks later ( Dad said only other Car that trounced that was a new 4bbl 289ci Studebaker firebreather)...
So at a pinch maybe that would help ? Temp running a reversed opposite side STK manifold ?.
Good luck. T
Not an exact for your actual swap ( as not familiar with OEM 5.7 manifolds) but something that's always worked for us, eg getting down to a muffler shop etc after a swap: if say REAR dump ? Is to temp use passengers side with outlet facing forward clearing steering gear/brake booster etc & running pipe forward & under & back.
This should bring a few memories back to the old timers who had/ran '54 & up fords & mercs ,& F100's with the Y-blocks 272/292/312ci V8 converting stock single system manifolds over to duals ( when they were all the rage back then)
As an interesting aside Carcraft put a psi meter on the stock single downpipe system: a tapping after each manifold & @ 100mph got stock w single OEM muffler - 2.4 inches left, 1.7 inches right. Changed to duals with pair stock OEM mufflers & std manifolds: 0.4" inches BOTH sides NO other changes...the best they'd ever seen with a basically stock setup @ 100mph 4,000rpm (police interceptors of the time were fitted STK w duals,160hp)...Point of note dad telling me as a kid the 1st Y-block they got in at work from Ford, they had to remove that HOT exh crossover pipe that ran across in front of the engine & like the young racers they were thought they'd take it for a strop around the back streets late at night & this thing just CAME ALIVE with open manifolds, & a tram just happened along out of the blue, req evasive throttle & lit up BOTH rear skins leaving black lines for 1/2 a block for weeks later ( Dad said only other Car that trounced that was a new 4bbl 289ci Studebaker firebreather)...
So at a pinch maybe that would help ? Temp running a reversed opposite side STK manifold ?.
Good luck. T
