NAVYBLUE210

OP has PRC 215 Cathedrals with a much better E/I Ratio.
I still believe that a well balanced HCI, combo up to
600 Crank HP, 7000 RPM, below 4.0" Bore & 400 CI,
(lot of qualifiers LOL!) will perform better on street &
track NA with 1 7/8" VS 2.0" LTS.
My .02

Mike Morris

iTrader: (55)

I think the 2" is an excellent idea. Your current ones are way too small.

SoFla01SSLookinstok

Can't wait. Hope to get the order in this coming week. I think there is about a 2 week period after ordering the headers.

The 1 7/8 may be the best all around header for my combo. Although what I want most is 5000-7000rpm power. Seeing as my camshaft has a small amount of positive overlap I don't think the bigger primaries will hurt my tq too much at all. The main thing, in my mind, will be the reduction in pumping losses in the upper rpm range.

Maybe now it will finally put 500rwhp. Probably just get another 495-499. Lol.

big hammer

I think it'll do ok. You might find that you need more intake though

SoFla01SSLookinstok

Hopefully. Eh. I know the intake on the car is not the best. In reality the intake setup I have seems to be doing a pretty good job.

big hammer

A ported 92 is a good intake. But everything has its limitations. If it flows in the 280 range you may be at its limitations.

SoFla01SSLookinstok

True. That's probably what I would guess the intake to flow.

64post

iTrader: (5)

I still contend an 1-7/8" will be enough. Buy a good intake and TB.

SoFla01SSLookinstok

That may be. The intake setup on the car now is not bad. Do you mean go to a single plain setup or something?

Going with the 2" headers, on my motor, is me just taking the leap. I've read a lot about header size & it is still in the tumble. Lots of people move up in header size & see no gains "at the track". Some people do see gains. Just going off the trend with the LS heads they seem to like bigger primaries. Also depending of coarse. Some guys with around 450rwhp 347ci motors see very good gains, through the entire powerband, moving up to 1 7/8 from 1 3/4. I'm also pretty sure there are some high revving 347 combos with 2" primaries. If it works, awesome. If not, my fault. Heck Pipemax has 2" headers right on there, with my combo, for better mid to high end power. Exhaust system operating range of 4200-6700rpm. 1.75"-1.875" for better low to mid power in that rpm range.




I might as well put an LS3 top end on the motor right? Then will it run 10's or something? Lol.

Darth_V8r

iTrader: (4)

An ls3 top end isn't a bad idea, but the bore is too small. I know you were being a little facetious there.

Helping the motor evacuate more air isn't ever bad. If you're looking to upgrade your headers already, might as well do 2".

I get a little less hung up on E/I ratio etc. I tend to look more at the whole system. I do think when you upsize your headers, you'll expose or augment any shortcomings of your induction system. You may want to consider doing them in conjunction with each other.

JakeFusion

iTrader: (7)

MAST 240cc LS3 for the 3.9" bore would be a rabble rouser on a 383...

Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.

Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257

64post

iTrader: (5)

I'm talking about a ported Fast 102 or MSD. More to gain there than 2" primary headers.

big hammer

This is my word

big hammer

I would tend to agree. But while he's at it he might as well get two birds stoned at once

Darth_V8r

iTrader: (4)

I don't disagree at all here. But I doubt he's got the hankering to build an entirely new top end. And really shouldn't need it to hit 500 where he is now. **** with his current heads, the right LLSR should get him there coupled with short runners and large plenum intake

JakeFusion

iTrader: (7)

Yeah.

I just wonder what that setup would do tho... 550+ out of a 383?

big hammer

I would think so. Imo that would be the hot ticket for a high zoot 383

64post

iTrader: (5)

Who would waste those on a 383? Oh wait.....

ddnspider

iTrader: (26)

Please put a ram air setup on it

https://ls1tech.com/forums/generatio...k-setup-3.html

SoFla01SSLookinstok

Hey spider,

I'm just not that interested in the ram air. My car is slow.

I've actually thought of how your car is doing. Any track time/mph?