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454 Question

mtnman210

mtnman210

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I've been reading up on rebuilding the 454 that came with the k5 when I bought it. I looked up the casting number and it shows that it came from a corvette and with a hp of 270. Now I'm fairly new to working with engines so I'm seeking some advice. I looked up some newer 454 crate motors and they show around 425horsepower and 500 lbs of torque. Can I get those kind of numbers from my block without superchargin it or using nitrous?
 
easy to do with the correct parts. and just about as easy to hit 450 hp. but bbc motors hit a kind of big wall at around 500 or more hp with out big parts and milage concers. but yes to your question.

p.s. dont forget you want tourqe to get big stuff moving and then hp to keep it moving. are big trucks need bottom end grunt not all top end power.
 
Yep, sure can. Its so low, because it was probably from the era of high emissions requirements, so low compression, lotsa smog crap. Raise the compression, better flowing heads, big valves, and your ready to rock. I got a 454 out of a part suburban, was planning a fairly stock rebuild, saw it was 4 bolt mains and went hog wild. It was factory rated at 235 I believe, according to desktop dyno(of course its now a 496), it is now 460hp, and 600ft/lbs :D :D
 
wow awesome responses...Thanks guys
I was hoping that was the answer. it just got me nervous when I saw the low numbers. I went with the BB for the UUMMMPPFFF it would give me. So I was just caught off gaurd.
The other concern I've run into is that it's showing it as a 2bolt main. Now I haven't torn into so I don't know for sure. But if it is can you change a 2 to a 4 bolt main.
 
you can, but unless you are planning an 800hp 7k rpm screamer, its not neccesary. I overbuild anything, which is why my motor has eaten 3 th400's.....;)
 
thay say sbc can take 450-500 hp on a 2 bolt block with cast crank. but like above no need for 4 bolt just iceing on the big cake.
 
k20 said:
unless you are planning an 800hp 7k rpm screamer,
Click to expand...
It'd be kinda fun :D :D

But nope just something fun to go play in the mud with and maybe muscle by a few heeps I come across on the trail :grin:

so are you saying I shouldn't even bother putting the th350 back in?
 
th350 may last fine. First time, it was just due. Tranny guy said it was the original 16yo tranny build still in the truck, burned it up the first week I had the motor in it. Then drove it, burned it up again, overheated the tranny offroad I believe. Never shifted right after that, then it puked up. Then One day leaving school heard a weird noise, was shifting weird, pulled the dipstick, I had metallic paint for tranny fluid. Was really cool lookin, but ended up the torque converter bearing came apart. That was a mess. Only reusable parts from that one were the case and the output shaft. Everything else was garbage.

If it happens again before I think it should, sm465 or nv4500 here I come.
 
good built th350 will hold o.k but whatch the temps. best to go 400 if possible. but the 350 is lower first gear. the 400 is higher first gear. the 350 is better in my opinon for that reason. and i had one in my old truck that was 6500lbs of 1ton and built 400sbc .
 
My plan was/is to just use it till its done and then swap in the th400. heck I have it so I might as well use it right?
 
Low "ratings" dont mean low power!

Most GM motors after 1972 were rated differently than the earlier ones---they decided to measure torque and horsepower at the driveshaft after 72,with all accessories installed..before that it was right at the flywheel on a dyno,with only the engine(no P/S pump,altenator,etc..)...thus the big "drop" in power on PAPER--but the engines themselves were not really THAT much weaker,despite the addition of smog pumps,compression ratio reductions and catalitic converters..

My 76 Caddy 500 is "rated" at 235 hp,and 360 ft lbs of torque...a 1971 500 motor with only slighty more compression is rated at 360 hp,and 510 ft lbs of torque!..a BIG difference on paper--but drive them both,I bet you could hardly tell the difference--they rated things this way mostly to reduce insurance costs,and to be more realistic as to the "real world" available power to the rear wheels--not just an impessive "dyno" number...A 1971 307 had 200 hp,and 300 ft lbs of torque--a 1973 307 has 115hp,and 205 ft lbs..I've owned both,and I could not feel the difference driving the same vehicle with both engines..

So dont use the "ratings" as a guide--I use the "seat of my pants" dyno!--I bet your 454 would put out much more than its "rating" if you had access to a dyno and put it through its paces!...It would probably suprise you!... :crazy:
 
if your looking for a 454 that makes 425hp/500 lb ft, why not the GM 454 HO crate motor?

http://www.sdpc2000.com/catalog/120...M-Performance-Parts-Crate-Engine-Assembly.htm

HotRod magazine test one last month or the month before in an Engines issue.

with a 825cfm Mighty Demon and a set of Headers, it made like 472 hp and 562 lb ft on the dyno.

one of these days i will get around to taking mine of the stand and putting it into the engine bay. :D
 
I saw those and they are great motors I put a new crate 350 in my DD blazer about 2 yeards ago. But the 454 came with the truck when I bought it so I'd rather just build up the one I have. It will probably be about the same price as buying new or maybe a little more. One of the main reasons I got the truck was to learn as much as I could by doing everything myself.
 
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