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.

 

 

Thank you, i appreciate your response, i guess nobody else wanted to touch on the subject..

 

Not many people will have used a Mondello Posi-flow, its just a Offenhauser intake with name ground off and the price raised. Id go ahead and use it, with a 800-850 vacuum secondary carb. You may lose a bit of off idle torque, but should gain midrage and top end.