I have my 540 waiting to go in in a couple of months. I am trying to gather up all the peices for the install first. The motor dynoed at 714 hp. and 655 tq. I am upgrading the cam, so power should go up a little. I plan on running the 3.5" exhaust from torque tech, but wanted some opinions on fit and finish. I don't think I will get away with running 3". Also curious what mufflers people were running? I was thinking of the Flowmaster 40 series. I know it will be loud, but my neighbors already hate me from my truck 4" turbo back exhaust. Thank you all in advance for your insight

Is this a DUAL 3.5" kit? I would think that might be too much. I have a dual 3" kit soon to go in for my 540.

Yes it is dual 3.5". How much power do you have? I might opt for a 3" if it won't kill power.

mph131 I am running a 505 dynoed out@637hp without any tuning. Looking to get 685hp out of her. This is in my 69 Chevelle SS. I am using the Torque Tech 3" exhaust with Flowmaster 40 series. First night out the local officers told me to take it home. Way to loud.It is nice though. My wife can here me launch it 1.5 miles away without a problem. The torque tech fit right in place. The left side was put in place in 35 minuites after jacking the car up. Without tightning anything up. The right side gave me a little problem. The header was not straight and level with the car. If you go with their system. Get the collector flange that is not welded in place. Then you should be able to make the connection to muffler. Then weld the flange to pipe after being set in place. The 3" fit right in place. No clearance problems. I am going to switch to 3.5" from header to muffler and keep the 3" from muffler to rear. Not sure which mufflers yet. I know the 40 series have to go. A buddy of mine put the 3" system on his 68 Camaro. It fit great. I hope this helps. Both systems were located in the original locations.

Originally posted by mph131:
Yes it is dual 3.5". How much power do you have? I might opt for a 3" if it won't kill power. Can't say for sure, didn't dyno it. I suspect it isn't quite as much as you. Are you going to race this or is it a cruiser? Mine will only see street duty.

I run 3" pipes thru Dynomax Ultra Flow welded ovals to 3" turndowns... street or strip it does fine.
What size headers are you planning? I use Hooker Super Comps with 2 1/8" primary.

It will be mostly a street car. I may run it at Raceway park, but have no cage. Is their much sound difference between 3" and 3.5". I will most likely run Hooker Super Comps 2.125" primaries.

FWIW I'm running Hooker Comps with 2" primaries. I didn't want the hassle of that tube around the frame. It's already hard enough to get those headers in there.

Iam also running Hooker Comps 2" primaries

Originally posted by ben70:
I didn't want the hassle of that tube around the frame. It's already hard enough to get those headers in there. Actually, these are probably the EASIEST set of headers I've ever installed on a BB. graemlins/thumbsup.gif
Both sides probably took 45 minutes to install.

My son's Chevelle has had both 3" and 3 1/2" with Borla mufflers and both worked equally well. The Borla XR-1s are relatively quiet and don't hardly slow the cars E.T.s at all. I think they are the best mufflers built and are the most efficient when placed as far back as possible. So far the best motor pass is 9.56 @ 140.27 thru these exhausts.

I'll probably wind up using the 3.5" with the longest muffler I can find that is a true 3.5" throughout. If I lose a little power thats OK. There's always nitrous...

If you're about to buy it all, I'd go for the 3.5" for sure. Big motors need some flow, especially when going all the way out the back.

JIM

I am also planning on running the X pipe setup. Will the X pipe quiet it down some? Is their any drawbacks to an X pipe? Everything I've read has been positive.

Originally posted by Harold Sutton:
My son's Chevelle has had both 3" and 3 1/2" with Borla mufflers and both worked equally well. The Borla XR-1s are relatively quiet and don't hardly slow the cars E.T.s at all. I think they are the best mufflers built and are the most efficient when placed as far back as possible. So far the best motor pass is 9.56 @ 140.27 thru these exhausts. Harold,

If you don't mind me asking, what part number Borla muffler did your son use on his car? To start out with, I'm using the 4" in/out #40948. I'd just like to see what he used for comparisons sake. Thank you in advance!