Omerta88

Today i got my 454 from an 89 suburban and i had fun check it out....the motor has oval intake ports i know 454 had two diff ports...whats the diff

Atilla the Fun

'89 was most definitely peanut port only, unless it has a pre-'75 version swapped in. that driver side exhaust manifold might just fit. That a/c setup sure won't fit under the hood.

mr03chevy

change it to square port also make sure it's a four bolt main.... i did it on my iroc and it's awesome....

mr03chevy

good luck man i did it with mine and it's well worth it!! make sure you get a hi perf set of square port cylinder heads and a square port manifold.... i did it on mine an it is breath taking....

Atilla the Fun

you don't need 4-bolt mains or rectangle port heads for 6000 rpm. The heads you have are a reasonable cam away from 415 horses at 5000 rpm. If that doesn't suit you, World Merlins in the large oval version are the best bang for the buck.

Omerta88

i think im gonna go with what i have now and prob play with it more later....will the turbo 400 fit in there or no because i know the third gen has an ungodly small trans tunnel

Omerta88

no ac for sure and ill be geting a set of patriot headers

Air_Adam

It will have a set of peanut port heads on it - around 210cc or so. The large oval port heads, like my 781's are around 265cc intake ports. These are probably the best street/strip BBC factory head there is, they can support plenty of power with just bigger valves and some compression. The peanut port heads will support 400hp or so no problem though, and make a bit better low speed torque too. BBC has a pretty bulletproof bottom end, so no need for 4-bolt main caps untill you're getting into absurd power levels. The 2-bolt blocks are still very strong.

Omerta88

NOW EVERYONE IS SAYING PEANUT PORTS....I ASSUME THE LOOK LIKE AS NAMED RIGHT? I TOOK THE INTAKE OFF AND THEY LOOK ALOT MORE ROUND THAN PEANUT SHAPED ILL TAKE PICTURES OF THEM AND POST THEM SOMETIME TODAY OR TOMARROW...IM NEW TO BBC LIL DIF THAN A SBC TO ME

Atilla the Fun

TH400 fits just fine.

Atilla the Fun

They're called peanut ports because they're so tiny. The actual shape looks more like an oval. In the '70s, when the new tiny ports debuted, peanut was a bit of a common slang term in some circles, and meant anything that was very smakk. I remember some kids even got nicknamed peanut. This may have come from the comic by Charles Schultz, I'm not sure.
But no, peanut ports do not look like a peanut in any way. But after 35 years of ALL the Chevy guys calling them that, it's best to just go along with it.

Omerta88

lol i got it now thanks for clarifing.......now is there a big diff in a t400 from a suburban as compared to one from a car?

Atilla the Fun

not if the Suburban was 2WD. If it was 4WD, you can't use it's trans.

Omerta88

2wd so im good to go then

t-top havoc

iTrader: (3)

Looks like it will clear the firewall! Forgive my ignorance--if both sides are the same, is it just a matter of pipe work? I mean IF they clear the firewall, no BFH persuasion to the floors or framerail, then just a few $ for some custom pipe bends?
Can the air tube fittings be closed off?
I'm 'yardin' tomorrow, so I may be able to pick some up.

Omerta88

with it being A.I.R im not going to mess with it. itl never pass emission standard anyway. the patriot headers are real affordable and less of a headache im sure and from what i understand a BFH is needed for the pass side floor.

Omerta88

can the peanut heads be ported at all...or is even worht it?

Atilla the Fun

Actually, BFH'ing the floorpan may be the best thing. Don't do the subframe rail, but the floorpan is fair game. Might save you hundreds of dollars.

Atilla the Fun

Oh yes, most definitely yes, on both counts. The legendary John Lingenfelter himself ported a set, put them on a built rat, and got 600 horses from them. that was with a big solid roller cam, and bigger valves, but still, it shows that the potential is there. If you want to go that route, start by buying a set of 2.19/1.88" valves, and the intake gaskets for the early large-oval intake ports, NOT the big rectangle ports.
Have an automotive machine shop cut the heads to match the valves, then do a 75 degree bowl hog to follow up. Then you're ready to start porting.
This is one of the most challenging porting jobs going, and it has a few easy tricks that really help. If you go this route, I'll give you more details.

Atilla the Fun

Better to just test fit with the manifolds, including pounding the floor, because the Patriots require pounding anyway. If the manifolds clear, just plug the AIR holes for now, headers can wait until you get done replacing everything else. Like the soon-to-be-broken rear axle. :-)
But if the budget allows, now is the time to do headers. If so, I definitely will offer to buy at least the driver side manifold, haven't seen the other yet.

Omerta88

i will get pics of them both today.... i am doing the headers now because the motor is out...tell me a more about porting thease heads

Atilla the Fun

The biggest problem with porting the peanut ports is the risk of breaking
through the port wall into the pushrod area.
Experienced porters can hear when the wall has already gotten too thin,
but too late is still too late.
One trick is before starting any porting, measure the port opening.
Cut a piece of white cardboard to match, then crazy glue it to the tip of a pencil.
Do a bunch of these.Split in to 2 groups. One for the long ports, one for the short
ports. Do the following to each set. groups, aLabel the first one 0.5, the second 1.0,
and so on.
Trim the first one until it exactly matches the ports 1/2" into the port. Trim
the second one to match the ports 1" deep, and so on.
Then get blue and red sharpie markers. Draw a line down the center of one intake
port floor, then use it to make a corresponding dot on each template.
Then cross-mark the port floor at each depth you can.
Then use the templates to mark the other 7 intake port floors.
Then, when you're porting, with the decks down, don't grind on the port floors.
Focus on doing the other 3 sides about equally.
grind, then try your template to check your progress. Use the red lines and
dots so the template stays centered left to right.
It's fairly safe to remove up to 1/8" around the 3 unmarked sides of the templates.
this technique will help you do consistent work.
It's better to leave too much iron than to hit water. If you hit the pushrod area,
JB Weld is your new best friend. All you're really risking there is a vacuum leak.
There are many more good porting tips in my thread on porting DIEs
(Dart Iron Eagles, though that thread is moving in to other heads)

Atilla the Fun

The valves are a fairly large expense, you need stainless, swirl-polished valves with undercut stems, Have the shop put a small 30 degree back cut on each and every one of them before cutting the seats to match.

Omerta88

awsome i will print that out....im takin the heads in tomarrow for machineing and ill see on geting into porting them....thanks alot for the tips i will keep this thread updated as i progress

Air_Adam

IMO, you'd be better off to spend your money on a set of used 049 or 781 (they are basically the same) heads and rebuilding those, than throwing money at the peanut port heads to have them ported - the peanut ports will do better with porting, but not like the 781 or 049 'large oval' heads will. 781 heads are not rare by any means, so you can pick up a serviceable set for fairly cheap still - MUCH better way to spend ones money IMO. A set of stock 781s will do what a set of ported peanut-ports will, and if you port the 781s, the peanut port heads will never catch up to them, no matter what you do to them.

Guest

Ported peanuts surpass unported large ovals. Why else would Lingenfelter say so?

Atilla the Fun

I think we should clarify this. Lingenfelter-ported peanuts beat unported large ovals.
However, in my area, finding rebuildable large ovals run $500 per bare pair, while peanuts are under 40% of that. By the time you get hardened seats, new guides, resurfacing, and the valve job, you're the same money for the large ovals as just buying new bare world Merlins.

Omerta88

im not going to port them just yet but they are geting machined and microfluxed today...when its in the budget i will look into my options for heads....at 150 a head for machineing and valve seats....ect im ahead for now....no what i mean.....and attilla i will hopefully have the pics of the manifolds today if time alows me too

Atilla the Fun

Thanks, I'm not in a big hurry.

Air_Adam

But then you've gotta buy all the same parts for the Merlin heads too - and why would you need to add hardened seats? Not all of them came out of the '60s. Mine are '75 castings and already have hardened seats.

game1939

sounds real fun

Atilla the Fun

I've never actually found even one virgin large-oval BBC head that didn't have bad exhaust seats. Early flame hardening didn't work. It was still too new, not refined enough. they also tried electric heating to harden, but that was just as flawed.
Now, Merlins come already fitted with hard exhaust seats and new guides, and a valve job, so no, your argument doesn't stand. Yes, both still need springs and so on, but neither of us actually typed that. You just inferred it.
Anyway, by the time GM got the exhaust seats right, the peanuts had replaced the large ovals.

Atilla the Fun

a few years ago Hot Rod did a junkyard jewel 454. It had peanut ports and 7.75:1 compression. With a Performer type intake from World, and a 228/238 cam, it made 414 hp at 4900 rpm, if I remember correctly. They swapped to the Merlins, no other changes, and it jumped to 449 hp at 5400 rpm, again, if I remember correctly. I have that article in my files, but haven't seen it in nearly 2 months.
35 HP isn't much for $1,000 but the extra rpm range means they're gonna be worth even more HP with a bigger cam.
They are better out-of-the-box than entry-level-ported production large ovals from GM. They're certainly not cracked, and they have more iron in them for more extensive porting.
Still, that 228 cam is a street/strip grind for an 8:1 454, and with that cam, 35 hp doesn't justify $1000.
If you do pull your heads, and you don't find domed pistons, you can help your compression a bit with these: http://www.summitracing.com/parts/MRG-1131G/

Omerta88

well Today i had some bad news one of the heads is cracked

Omerta88

is it possible to do 8.8 rear end from a mustang to bolt in directly and will it hold up to a 454?

Atilla the Fun

Getting it to hold up is the easy part. Doing a torque arm bracket is the challenge.

Omerta88

well im crafty for the most part is there an upgrade i can do to my a$$ end to hold up a 454?

Atilla the Fun

spend some time in the trans and axle sub-forum, that's part of why it's there.