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Discussion Starter #1
on a stuska dyno(sp) my junk made 535hp @ 6500 rpms it is a 377 sbc heres the run down 4.155 *3.48 13.8-1 dart race series220 heads std port flows 298 @[email protected] super victor 1000 cfm pro systems stage iv custom ground comp cams aprox specs 272 280deg .730 .740 on a 108 the dyno headers they used were 1-5/8*3 I am going out there in the am and we are putting my headers on which are 2"*4"with dynomax bullets can i expect any gains? thanks Glenn
 

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I am going to say yes. I have seen a header change pick up 20. This thing has a monster cam in it whitch I think may be throwing your combo off.
 

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Discussion Starter #3
well i was thinking it should be making 100 more hp mabee the numbers are uncorrected something seems off to me the cam i had in it before was way wrong..........and according to hp/et calculater made 521hp...................ill post the sheet tomorrow. Glenn
 

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Yes I think it's down on power also something is just not happy. I think RPM is on the low side also for this size stroke. I would want to see upper 7s to lower 8,000 RPMs for peak.
 

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The heads dont flow that well, why worry what the .800 number is your not even getting close to it. Look at the .500-.600 numbers. The 2 " headers with a 4" collector is way to big for it, carb looks big too. Your not going to see any big change. I dont think and I think TQ will fall off too post your sheets. Cams can be way off on these style motors and it will mean 30 hp
 

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Discussion Starter #6
thanks the head # is the only one i remenber, I agree we are going from to small to too big im probably being optimistic when i can afford a set of 13/4 to 17/8 step header they will be there. comp speced out the cam according to everything else.................its kind of depressing I could have bought a really nice proven crate engine for what i have in this thing.
 

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I think your cam is a good choice if that is the true comp ratio...
It should be making 635HP not 535

My 358 with sportsman 2 heads 13.6:1comp and 278/286 on 109 make 655HP at 8100rpm, just to give you an idea and i have 1.75 primary pipes
 

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Drop the duration down 8-10 degrees tighten lobe sep.to106-107 .lift is ok.use 1/3/4 header.are you absolutely positive comp ratio is 13.8 or is that a guestimate?Bill C.
 

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Discussion Starter #10
Drop the duration down 8-10 degrees tighten lobe sep.to106-107 .lift is ok.use 1/3/4 header.are you absolutely positive comp ratio is 13.8 or is that a guestimate?Bill C.
thats what it was before this rebuild the deck was surfaced and different head gaskets are used so it could be off .2 or so i will get cranking psi tommorow as well!
 

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Discussion Starter #11
thats what it was before this rebuild the deck was surfaced and different head gaskets are used so it could be off .2 or so i will get cranking psi tommorow as well!
also heads are 55cc chamber dome is plus 5cc including valve notches deck hight was-.008 before the surface cut cant remember the vol of the mls gaskets from before...............
 

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Butch
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Drop the duration down 8-10 degrees tighten lobe sep.to106-107 .lift is ok.use 1/3/4 header.are you absolutely positive comp ratio is 13.8 or is that a guestimate?Bill C.
I would keep the duration and go 104 to 106 based of prior performance

We are making more than that shown by ET's with a GM crank, 5.7" rods, TRW pistons and as cast Dart Heads from 30cid less or so (4.030 x 3.25)
 

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Discussion Starter #15
Thanks for all the replys with the 2-1/8headers &4"bullets it made [email protected] from6700-7100 it was gaining 10hp per 100rpm we ran a last pull up to 7600 but the collector came off the compression is only 12.5-1 and the bsfc was all over the place and also it wants more carb going fat above 6700rpms......................I will not have the sheets until i pick up the engine tommorow or friday i will post them then I am pretty happy with my junk heads carb and headers..........................
 

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Discussion Starter #16
Thanks for all the replys with the 2-1/8headers &4"bullets it made [email protected] from6700-7100 it was gaining 10hp per 100rpm we ran a last pull up to 7600 but the collector came off the compression is only 12.5-1 and the bsfc was all over the place and also it wants more carb going fat above 6700rpms......................I will not have the sheets until i pick up the engine tommorow or friday i will post them then I am pretty happy with my junk heads carb and headers..........................
my carb is not junk because of pro systems its junk because it has been 10 years since i got it and it hasnt been back since
 

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My 379 c.i. small block made 649 [email protected] & 509 [email protected]
My combination is 4.155x3.50 11.5 to1 comp. 93 octane pump gas. Track 1x cylinder heads [email protected] int [email protected] exh .660 lift with 1.6 ratio rocker. Dart intake and Holley box stock 950 carb. Using 1.875 primary tubes & 3.5 collector. Also the cam is on a 107 lsa. Book grind from Comp nothing fancy.

This is proven power, My 3150 nova has been a best of a 9.72 at 136 mph with 1.27 60 ft.
 

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Discussion Starter #18
My 379 c.i. small block made 649 [email protected] & 509 [email protected]
My combination is 4.155x3.50 11.5 to1 comp. 93 octane pump gas. Track 1x cylinder heads [email protected] int [email protected] exh .660 lift with 1.6 ratio rocker. Dart intake and Holley box stock 950 carb. Using 1.875 primary tubes & 3.5 collector. Also the cam is on a 107 lsa. Book grind from Comp nothing fancy.

This is proven power, My 3150 nova has been a best of a 9.72 at 136 mph with 1.27 60 ft.
Thanks Heath Im going to put it in and see what it will do! And the start refining it one thing at a time. What gear tire & trans do you run? Thanks Glenn
 

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I run a 4.88 rear gear 30x10.5 Hoosier radial slick turbo 350 trans with brake. Goes through between 8400to8600 depending on weather conditions. Also running a 6200 stall speed on the converter. You really have to rev these short stroke engines but I love how they sound!!!!
 

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Butch
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My 379 c.i. small block made 649 [email protected] & 509 [email protected]
My combination is 4.155x3.50 11.5 to1 comp. 93 octane pump gas. Track 1x cylinder heads [email protected] int [email protected] exh .660 lift with 1.6 ratio rocker. Dart intake and Holley box stock 950 carb. Using 1.875 primary tubes & 3.5 collector. Also the cam is on a 107 lsa. Book grind from Comp nothing fancy.

This is proven power, My 3150 nova has been a best of a 9.72 at 136 mph with 1.27 60 ft.
Glen that is a couple degree's smaller than what I talked to you about
 
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