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454 engine question

C

codytr1

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I'm getting read to pull my bone stock 454 from my 85 K5, I'm looking to freshen it up. I'm hoping to reuse all stock bottom end parts. I picked up a pair of 3964290 heads CHEAP they have 2.19/1.88 valves the have about 400 miles on them! I'm planning on using a comp xe268 or xe274. My question is will this be a good combo or should I work the peanut ports? I have been on the internet for a couple of day researching.... By the way the Blazer has SM465/205 14FF 4.56 35 Hawgs and she is not a trailer queen. This needs to run on 91 octane. Thanks for any input.
 
Peanut ports are worthless IMO, I'm to lazy to look up those casting numbers, but if they are oval ports, use em.

Dont just toss new heads and a cam on a tired bottom end or you will regret it. Atleast toss new bearings and rings in the bottom end to get the most out of it. New gaskets as well.
 
454Sub said:
Peanut ports are worthless IMO, I'm to lazy to look up those casting numbers, but if they are oval ports, use em.

Dont just toss new heads and a cam on a tired bottom end or you will regret it. Atleast toss new bearings and rings in the bottom end to get the most out of it. New gaskets as well.
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:eek1:
OH NO! it is going to go to the machine shop and getting all bored, honed and stuff. The heads are 396-454 CID CLOSED Chamber 109 cc or 101cc depending on what site you go to.
 
you should look for 781's or 049's for an open chamber piston shortblock.
 
codytr1 said:
I got a set of bare 781's but the machine shop quoted me like 750.00+ to get them done. For that money I can get some World Products Merlin heads.
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oops maybe its not such a bad deal for 781s just read the Merlin heads 800.00 a piece not a pair. :blush:
 
I agree, 781 or 049 heads are the way to go BUT these with a stock piston will onl give you about 7.9:1 comp. I would suggest getting new pistons but I understand that causes the snowball effect.
 
hahaha, yes it does!

next thing you know, your up to 3500$ or more.

You could put some clay on top of your pistons, and roll the engine over to see what kind of clearance you have between the valves and pistons....not sure if the flame travel would be an issue with CC heads on the OC pistons though.
 
76zimmer said:
hahaha, yes it does!

next thing you know, your up to 3500$ or more.

You could put some clay on top of your pistons, and roll the engine over to see what kind of clearance you have between the valves and pistons....not sure if the flame travel would be an issue with CC heads on the OC pistons though.
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The more I think about it the better this build sounds.
http://www.carcraft.com/techarticles/ccrp_1010_cheap_big_block_chevy_engine_build/viewall.html


thanks to Ned Kelly I've read this twice tonight.
icon12.gif
 
The comp cams head cc kit is only $10. I have one. Totally worth it to verify chamber size. Which seems to be a problem with BBC heads
 
The "290" castings are square port heads and WAAAY to big for a truck engine, those are for top end HP for a race car. You want "781" heads then have 2.19/1.88 valves installed then blend the bowls.
 
John (80'427) made good power with peanut ports. They are not as bad as everyone makes them out to be.

Martin
 
They really aren't that bad for off-road use. Too small for high RPM applications but it doesn't sound like that is what you are building for.
 
I heard the ideal range for each type of head is as follows:

peanut ports...idle to 3500rpm
large oval ports...idle to 6000rpm
large rectangular ports...3000 to 7500rpm

that article supports the peanut port heads, and it shows the flow good up to 4500 or so, but the engine probably has some left on the table with those heads too.


I agree with Scott, in that the large rectangular ports are for higher rpm use. Not that the engine won't be good down low with them, but there are a lot better heads out there for a heavy truck to make low end power with.
 
76zimmer said:
I heard the ideal range for each type of head is as follows:

peanut ports...idle to 3500rpm
large oval ports...idle to 6000rpm
large rectangular ports...3000 to 7500rpm

that article supports the peanut port heads, and it shows the flow good up to 4500 or so, but the engine probably has some left on the table with those heads too.


I agree with Scott, in that the large rectangular ports are for higher rpm use. Not that the engine won't be good down low with them, but there are a lot better heads out there for a heavy truck to make low end power with.
Click to expand...

I appreciate all of your guys' input it really helps
 
The 290's should be good and will help with compression since you plan using a stock-ish bottom end.

I think Scott was thinking about the 990 casting heads.
 
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