What size primaries for LTs with my set up???

[N8Miller]

I am switching out the shortie headers that i have for a set of long tubes in about a month or so. i was told that 1 5/8 would be good becasue you need that back pressure and velocity, but others have told me that 1 3/4 would be ideal. i just wanted to see what everyone had for opinions and what size they went with on their set ups.

 

[90mustangGT]

I don't think it would make much difference. You might loose a pound or two to tq but would probally make up for it in hp.

Remember, you don't want any backpressure, you want to keep up velosity to increase scavaging.

 

[MORFORD]

I went with 1 3/4 on mine because I figured it would be much better for a 150-200 shot. It's just a mild 302, and it didn't seem to hurt torque at all na. It depends how high you are going to rev that 331 and how much power you plan on making. I think the 1 3/4 would be fine, and if you wanted to add a blower or n20 later, they would definately be better.

 

[N8Miller]

I went with 1 3/4 on mine because I figured it would be much better for a 150-200 shot. It's just a mild 302, and it didn't seem to hurt torque at all na. It depends how high you are going to rev that 331 and how much power you plan on making. I think the 1 3/4 would be fine, and if you wanted to add a blower or n20 later, they would definately be better.

i would like to make about 330-350 to the wheels when im done with the motor----and i pretty much am. I am going to run a 100 shot too and maybe up to like 125 or 150 depending on how close i get to the 11s.

anyone else???

 

[Bling]

I'd go w/ the 1 3/4. You'll only be going up with power, so no sense in limiting yourself now. Best thing would be to get some 1 3/4 with a true 3in, 3 bolt flange collector. Not that ball and socket stuff on the BBK's and MAC's.

 

[PURESTREET5006]

I have 1 3/4 race headers on my 310 SBF...You get can get away with those and be happy with the mid range and top end you'll pick up