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Discussion Starter · #1 ·
I'm hot ridding my 85 gmc Sierra with a 454! I need some tips on what to get next because I already bought a cam and a set of hooker headers. It still has stock manifold and quadrajet carb, the cam is an xtremeenergy xe274h-10
 

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I wouldnt use the rectangle heads unless you are serious about power. Ported GM oval ports with 2.19 valves make a fair amount of power. then after market ovals then squareports. If you already have the heads,put them on a flow bench before buying a cam.
 

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the cam I found was [email protected] 50,550 lift and a 4/7 swap?hydraulic flat tappet? probably would use a performer air gap and 850 cfm carb. if you have room for a 4 inch exhaust and the price is fair?true duals with x pipe. 3 inch min
Vinnie the part # for the big block cam is 11-246-3. It took me awhile as I was looking at the 4/7 swap cam too.
 

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the square port heads flow a lot and can make over 700 hp. Are they closed or open chamber? after you flow test the heads you pick a cam that fits the flow chart. Oval port heads can support over 500 hp if ported.2.19 intake valves are also a good choice.

my 1980 z-28 with LS-5 454 took me into the high 11s. I doubt it was 375 rwhp. I used GM oval port heads with 2.19/1.88 a Z-55 isky cam,Jr oval port manifold,830 annular double pump holley,flat top pistons, open headers.car weighed 3915 when I bought it and managed to get a little over 300 pounds out of it.
 

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Discussion Starter · #9 ·
Yeah as much as I'd like to put the rectangle port heads, it's just not really for the set up, and they sort of came with a package deal , but I can see that I can get possibly 550hp out of the oval heads . And does an eaton posi with 3.73 sound like a right combo for the 454 too? With a 400 transmission
 

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3.73 is a decent gear,what tires are you using? Anything less than a drag radial and I doubt you will hook up. The 454 makes a tonne of torque. I used slicks on my car. just 9x 29.5
 

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Discussion Starter · #11 ·
I'm not quite sure , but I plan to use 18 inch rims and a set of the biggest tires I can fit under there haha , but say I get the oval heads ported with bigger valves do you think I could get to 500 horses? I already know ima have lots of torque.
 

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500 HP will be easy.get the heads figured first.Im not a big fan of hydraulic flat tappet,but they work well to 6,000 rpm.They tend to have a lumpy sounding idle way above the performance they offer.
I didnt ask,is it a 3/8 " rod bolt or 7/16s? if 3/8s for sure replace bolts. do a basic blue printing job on the engine,deck/square/align hone the block, 9 1/2 CR for iron heads,maybe 10 1/4 for aluminum, open plenum intake ( vic Jr oval port),850 cfm carb, decent headers. thats all it takes to get 500 hp from 460 cubes.
please do not use a dual plane intake, I took a performer off my 454 Camaro and installed the vic oval port and picked up 4/10s,,,, wow!!!.
 

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the connecting rods are 2 piece at the large end(where they connect to the crank) those bolts there need to be A.R.P. or better for good engine life. The heavier duty GM rods have one size bigger rod bold.after market rods are not required for a mild engine build,just meticulous assembly and attention to detail.
 

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Discussion Starter · #15 ·
Haha oh I knew it was something like that but I'm not sure. I havnt torn the engine that far down but yeah everything needs detail and arp has the bolts ya need! Lol but idk hopefully they're good. And I want your opinion on racing one of those 90 some ford mustangs;the ugly ones, lol how do you think I do against it ? I believe it might have a small block, I don't believe it's built too much maybe headers or something , but it might be a v6.
 

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What plans do you have for this truck? Do not buy any more parts until you know what your plans are. For street use the 781 and 049 (casting numbers) oval port heads are the most popular. You would need to cc the chambers so you can figure your compression ratio. Most rectangular port heads are used on engines for racing. Is this truck going to be a daily driver?
 
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