Will a 4150 PosiFlow Ruin My Throttle Response? Mild 455 Build
#1
Will a 4150 PosiFlow Ruin My Throttle Response? Mild 455 Build
I recently picked up 2 455s, one 69 Toro motor and a 70 98 motor. The Toro is fairly fresh so im just going to leave it stock and dump it in my wagon i recently dropped a decent 350 in. as for the 70, it needs bored so its getting flat tops. The build: i have a bare set of speed master heads, long tubes, a mondello 4150 posi flow intake and a 496\520 camshaft. I hear everybody ranting and raving over the performer intakes, the problem is i dont have a performer so naturally id like to use what i have. will a single plane make the throttle response go down the toilet? Honestly i think ill be just fine but im second guessing my self here.
On another note: this build is for my Stock 68 cutlass supreme, i have a 308 posi for it because i do more highway driving than anything and typical cruising speeds are anything from 70 to 90 mph. i have a few trans options as well, i dont want to use a 400 because im not cutting my drive shaft. i can use the 2 speed that is in it now (not going to), use a beefed up 350 (most likely) or spend money on a built 200 4r (want), figure ill use a 2500 Hughes converter Also i have not decided on a carburetor yet, was thinking something vacuum secondary for sure, maybe an 850 holley. As for exhaust im thinking Cherrybomb Vortex mufflers but probably no H or X pipe and absolutely NO Flowmasters... EVER...
In all honesty, am i really going to lose any thing running an open plenum? i figure its a 455 it should have plenty of torque anyway.
Alright now hit me over the head with your opinions.
On another note: this build is for my Stock 68 cutlass supreme, i have a 308 posi for it because i do more highway driving than anything and typical cruising speeds are anything from 70 to 90 mph. i have a few trans options as well, i dont want to use a 400 because im not cutting my drive shaft. i can use the 2 speed that is in it now (not going to), use a beefed up 350 (most likely) or spend money on a built 200 4r (want), figure ill use a 2500 Hughes converter Also i have not decided on a carburetor yet, was thinking something vacuum secondary for sure, maybe an 850 holley. As for exhaust im thinking Cherrybomb Vortex mufflers but probably no H or X pipe and absolutely NO Flowmasters... EVER...
In all honesty, am i really going to lose any thing running an open plenum? i figure its a 455 it should have plenty of torque anyway.
Alright now hit me over the head with your opinions.
#2
In my experience, 455 Olds don’t have a torque curve, more like a torque “plain”. I ran a performer for years, got a smoking deal on a Torker. I didn’t notice any lose in throttle response or low end torque, but did pick up about a tenth on the track. I did need to loosen the wrap on the air door of my Q-Jet to get that gain.
#4
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