1985 454 best heads to use?
02-04-2017, 11:26 AM
#11
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Is there any links on internet showing data sheets/Dyno results with that combo as a comparison to the 370 hp 454 that I had to begin with
I looked into replacing the rochesters with efi carbies and estimated the cost to be $2500 per engine so if performance increase is only slight then it's not worth it
I looked into replacing the rochesters with efi carbies and estimated the cost to be $2500 per engine so if performance increase is only slight then it's not worth it
02-04-2017, 12:45 PM
#12
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there are 1,352,751 threads on building 454s on this site.
But you need to tell us what specifically you want to accomplish and your budget....
You could easily build a 420 clone, a 420 clone with better heads... Do you want to go with a roller cam? Do you want to spin 5000 rpm or 6200 rpm?
a basic vanilla build of a stock 454 mag bottom with budget friendly EQ heads, or a little more for Big Al's heads or a lot more for some AFRs, something somewhere between a 731/ 741/500 efi roller cam setup and valvetrain, a set of used sm's or gills could get you in the neighborhood of 450-500 hp easily but each setup would be a little different.
But you need to tell us what specifically you want to accomplish and your budget....
You could easily build a 420 clone, a 420 clone with better heads... Do you want to go with a roller cam? Do you want to spin 5000 rpm or 6200 rpm?
a basic vanilla build of a stock 454 mag bottom with budget friendly EQ heads, or a little more for Big Al's heads or a lot more for some AFRs, something somewhere between a 731/ 741/500 efi roller cam setup and valvetrain, a set of used sm's or gills could get you in the neighborhood of 450-500 hp easily but each setup would be a little different.
02-04-2017, 02:27 PM
#13
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Correct me if I'm wrong, but EQ has a direct GM replacement head. You'll be able to use your stock valves and stuff. This is not the upgraded EQ 320 others are referring to with the better flowing ports. I belive you need different diameter and length valves for them.
02-05-2017, 09:32 AM
#18
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Yep. The EQ 320's, are basically the old RHS 320. They use an 11/32 valve like most Hi-Perf aftermarket heads. The GM heads use 3/8 valves. If he went to the EQ 320s, he needs all new hardware. IF he went with the replacement head, I believe all of his hardware can be transferred over. At least the valves. If the valves are good that is.
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02-05-2017, 09:43 AM
#20
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http://www.ebay.com/itm/MerCruiser-5...dTjkxd&vxp=mtr
Basically, its designed to be a replacment for the GM Rect ports. The intake runner is redesigned, and smaller , at 299cc. The chamber looks to be a more modern chamber design than the GM heads.
I'd want to replace the stock exhaust manifolds with something better, and a better cam than the 370HP came with. Add some roller rockers.
Stock 400/420hp 454 cam.
http://crane.carshopinc.com/product_...d/16042/132561
Basically, its designed to be a replacment for the GM Rect ports. The intake runner is redesigned, and smaller , at 299cc. The chamber looks to be a more modern chamber design than the GM heads.
I'd want to replace the stock exhaust manifolds with something better, and a better cam than the 370HP came with. Add some roller rockers.
Stock 400/420hp 454 cam.
http://crane.carshopinc.com/product_...d/16042/132561
