What size Pipes???

[Steelawork'n]

I have a 283 bored 30 over with an alluminum intake under a 600 cfm Holley. It has headers funneling into stock-like 1.5" pipes and standard mufflers.

What sized exhaust pipe should I be running?

[jsbgump]

i would run 2 1/4

[Longhorn Man]

2 inch would be more than enough onless you plan on spinning 7000 RPM.

[Gray Ghost]

I'd go with 2" as well....the smaller pipes will give you more low end power. Bigger pipes will rob it from you. Here's what I go by...

200-300 hp = 2"
300-400 hp = 2.25"
400-500 hp = 2.5"
over 500 = 3"

[MrC1]

I'd go 2.25". I don't agree with the myth that bigger pipes hurt torque. I've seen many tests that show no loss whatsoever. 2.25" probably costs the same and certainly flows better.

If you were turning 7000 RPM you'd want at least 2.25", but more than likely 2.5". I assume, of course, that this is crimp-bent pipe. If you're planning on mandrel bends, 2" would be plenty for a mild motor of that size.

[Gray Ghost]

Mandrel bent is the only way I'd consider it done on my truck. If you go this route, 2" is plenty good for your motor. Never seen a warmed over 283 hit anything over 5500 rpm and live.

I wouldn't even consider crimp bent pipes.

[stepside454]

If you plan to have traditional crmp bends , than Id go 2.25 . If your gonna have nice manderal bent exhaust, than 2" would be fine.

[JAKES 68GMC]

2 1/4in. If it's in your 68, I'd buy the whole 2 1/4in. exhaust kit from LMC for 150 bucks with mufflers and all.

[Steelawork'n]

How does the LMC kit fit? Is there any welding?

[JAKES 68GMC]

I've read it fits good, and it clamps together. You could have it welded if you want. My truck doesn't really have an exhaust, just rusty pipes cut-off under the cab.

[glock35ipsc]

Originally Posted by Steelawork'n

How does the LMC kit fit? Is there any welding?

I put the LMC kit on my 68 when it was still a long bed. It fit perfectly, and the turbo mufflers actually sounded real good too! It does come with clamps, but after I had everything where I wanted it with the clamps, I went back and fully welded it. I live on a dirt road that can be rough at time, so I didn;t want anything slipping or twisting. But it certainly can be done without welding.

Also, the kit is made up with mandrel bent 2.25" aluminized pipe. For the money, I think it is a great buy! You can get it exiting straight out the back (outside the frame rails from the axle back), or exiting just behind the tires.

[MrC1]

The LMC kit is mandrel bent?

How much is the mandrel bent kit? Is it available without the mufflers?

Dang, this sounds like the way to go for me, too. I was considering a quickie crimp-bent 2.5" system for my 402. 2.25" would be plenty with mandrel bends and it sounds like it might be cheap too!

[glock35ipsc]

Yup! Exit behind the rear tires is $199.95, and exit straight out the back is $229.95. That is with turbos. Glass packs or $10-$20 less. And the prices are the same for 2wd or 4wd.

[edit]Hmmm, now that I look closer at the catalog, they are only available for small blocks, which is

[MrC1]

That's weird. What's the difference between SB and BB on the pipes? I assume these kits are made to bolt up to the manifolds.

Do they offer a kit for use with headers? What about without the mufflers? (already got some decent ones)

[glock35ipsc]

The difference is probably the size, angle, and exact location that the pipe exits the manifolds. The BB will definately be wider.

There is no "mufler delete" option that I can see, and since they are made to bolt up to the manifolds, I suppose you could make a cut and weld on collectors.

[JAKES 68GMC]

That was my only concern, too, about the headpipes bolting up to the V6 manifolds.