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454 build up

15K views 56 replies 8 participants last post by  Horsepoweraddiction 
#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
 
#8 ·
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.
 
#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
 
#12 ·
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!!!.
 
#29 · (Edited)
Edelbrock Performer on BBC a poorboy

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!!!.
My experience with the performer On BBC is smiler, even with port matching (fair amount of grinding required) it was a wezzer, strictly for stock replacement not performance enhancement. the Weiand IMO is a way better dual plane.
I see theres a preformer "RPM" available now, thks cobolt, that would probley be more of a upgrade.
 
#14 ·
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.
 
#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.
 
#17 ·
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?
 
#23 ·
This is my first ever build, and I don't know everything, but I'm learning and I need all the help I can get. All I want is a truck I can race a little but still drive it on the road. My budget isn't the best but I'm willing to work a little. That's why I want to know what the right thing is to get because I have had no experience with motors before a year ago. I'm just looking for the best for what I got.
 
#26 ·
Before buying an intake, you first need to see what the casting number of the heads that are on the engine now to know where to go next, as far as buying parts goes.

There's a decent chance you have what's called "peanut port" heads. They make a lot of torque down low but not a lot of HP up higher in the rev range. The only intake I know of that's made specifically for the PP heads is Weiand's - p/n 8122 Street Warrior. For oval port heads, use Edelbrock p/n 7164 RPM intake.

If you want 500 HP, you'll need a set of oval port heads like the 049 or 781. Adding larger valves will help, but not absolutely necessary unless you're going to get serious- and if THAT were the case, I'd say to save up for a set of aluminum aftermarket heads.
 
#24 ·
Let me suggest an engine build. I will try and stay budget friendly, but this is a big block. Take the block, crank, rods to a machine shop to have them checked. If everything is good have the block bored .030, have the crank polished. The rods will have to be reconditioned. I hope they have the 7/16 rod bolts. Have them install new ARP bolts. Try and sell or trade your heads for a set of 781 oval port heads. Make sure the 781's haven't been butchered, you need 118 cc chambers so ask if they have been shaved. A good set of pistons is IC779 from Keith Black, they are forged. With 118cc heads they make 9.621 compression. For a camshaft I have 2 in mind. Both are mechanical flat tappet. 402ALUN .550/.570 lift and 238*/248* duration. Basic operating rpm range is 2400-6800. CRN 133841 .544/.567 lift and 238/248 duration. Basic operating rpm range 3000-6500. You will also have to purchase the solid lifters and spring set for the cam you decide on. I like the Lunati 402A2LUN. Intake Edelbrock 2904, Carburetor Speed Demon 850 1563010VE. The machine shop will also have to install springs on the heads. I am thinking of around 550 hp.
 
#25 ·
If you follow cdminter59 s advice,I would advise you to make friends with the local tire retailer as that engine will wear them out almost as fast as you can empty a few tanks of gas.If the rods are 3/8s and you limit the RPMs under 7k you probably will be fine,make sure you buy the good ARP replacement bolts
 
#27 ·
I have 3 sets of big block heads 1. 3856206. 2. 4081045 3. 346236 so I take it all of them are peanut ports? And 550 sounds great but I cant, definitely in the future ! But if those heads aren't the oval ports I need imight can try and find a set of the 049 or 781s. But if I can't get any I'll take vinnies advice and get the bigger valves and port a set of them.
 
#28 ·
The 236 are PP. I think the 045 are too.

The 206 heads (below) are closed chamber oval port heads. They will bring the compression up, but they don't flow as well as open chamber heads. The open chamber heads require a domed piston to bring up the compression.


There's an "in between" head called a semi-open chamber, like the casting number 215 and 063 heads. They are about 100-103cc. Open chamber heads are around 118cc.

Semi-open chamber on left, open chamber PP heads, right
 
#30 ·
Horsepoweraddiction, Can you give me the casting # off the rectangular port heads. I want to find out the chamber volume and port size. I have been looking online but there are too many heads with different size chambers. I was reading a couple articles comparing rectangle ports and oval ports. The oval ports performed better on the low end rpm but the rectangle ports caught up on the high rpm end. If you had them and money is a problem why not use them until you can afford something better?
 
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