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Discussion Starter · #1 ·
I seen in a post awhile back that you was thinking about going to two inch headers. In fear of upsetting anyone, I point out that I'm not saying that your wrong or it's a bad idea, just what I experienced.
In the S-10 that I raced I went from the 1 5/8 to 2 inch and it killed my torque. Just for comparision, the truck wieghed 3150 ready to race with out me in it. I had 4:56 gears, 205 in low range, 35 boggers rear, 36 swampers front.
5500 stall with trans break. Brodix heads, full roller, aluminum rods, it ran from 5300 to 7800 rpms. Even though it was stronger above 7000 I went slower.
They did sound cool though. I run 1 7/8 on that engine last year but it was in my rail, so I can't really help you compare there.
Just something to think about, maybe 1 3/4 or 1 7/8 would be something to consider. 1 7/8 or larger requires an adapter plate at the head for bolt clearance.

 
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Discussion Starter · #2 ·
Actually, they recommend 1 7/8, so 2" wasn't really in the plans. I could probably be fine with 1 3/4 - or maybe even a better set of 1 5/8. I have to run mufflers, so there'll be a little backpressure that way. My motor is a relatively mild hydraulic (well, not mild relative to most hydraulic motors, but nothing like a roller motor) one, but it is 408". My shortblock & cam should be good for about 470HP with the correct heads. Not sure what my truck weighs, but probably about 3,800. I run 4.37 gears with a 2.28 low range (comparable to 4.98 with a 2:1 t-case) in 2nd low (TH350) with a stock converter & Q78's at all 4 corners. I only occasionally go over 6,000 RPM's & normally that's just if it's a real shallow but slick start - although the Mrs. did run the entire length of the pit at 6,400 once when she forgot to shift/wwwthreads_images/icons/blush.gif.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #3 ·
Tex - The new Summit catalog shows the 1-chamber Flowmasters. I too think you'd be better off with 1-3/4" primaries. Just my opinion from what I've seen at the races and read.

BTW, what happened to that banner that was running at the top of the page the other day with the chearleader?? That was cool. /wwwthreads_images/icons/wink.gif

/wwwthreads_images/icons/cool.gif
'84 K20 driver
'79 K10 mud racer
'48 CJ-2A trail Jeep
 
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Discussion Starter · #4 ·
I may just have to get some of those suckers. Now, if I could just find a set of headers that'll fit w/o breaking the bank! Mudracer, you said you're running 3" exhaust on your Mouse, right?

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #5 ·
Yep, 3". Had Midas bend the pipes to match my sketch, then I installed them. Worked out nice, and cheap too other than the mufflers. They carry good quality aluminized pipe. My headers came from S&S.

/wwwthreads_images/icons/cool.gif
'84 K20 driver
'79 K10 mud racer
'48 CJ-2A trail Jeep
 
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Discussion Starter · #6 ·
What size pipes should I run on my 350? It has a rv cam, Eldlebrock performer intake and carb (600cfm), and is bored .30 over. Has around 250hp, maybe. I want to put headers and 2 chamber flowmasters on it. Muffler shops tell me not to use over 2-1/4" pipes. I was thinking 2-1/2 or 3? Also what is a good set of heads that wont cost a small fortune?

 
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Discussion Starter · #8 ·
I'm not exhaust expert, but I'd say that a mild 350 would do fine with 1 5/8 or 1 3/4 headers. 2 1/4 pipes would probably do fine, but I'd go for 2 1/2 in case you up the ponies in the future. You won't want 3" on that engine. Cams that work well with the Performer intake give real good low-end torque, but generally fall off pretty fast after 5,000 RPM's. 2 1/2" pipes won't hold you back at that kind of RPM & will help build a bit of backpressure for street driving & good low-end power.

Just my $.02. Any other thoughts guys?

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #9 ·
I'd go with 2-1/4". That's what I have on my driver with a TBI 350, RV cam and factory manifolds. For a driver you need low end torque and smaller pipes are better for that. Call Flowmaster for another opinion. Hedman headers are a good value - not cheap on quality, but fair price. I have a set I used to use that have held up great for several years. They go for about $100 for a set for a full size Chevy. I'd go 1-5/8" on the primaries, which is what you'll find most available.

/wwwthreads_images/icons/cool.gif
'84 K20 driver
'79 K10 mud racer
'48 CJ-2A trail Jeep
 
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