454 (7.4L) swap / repair options - 1999 Suburban K2500

[BNielsen]

Looking in my database from that thread, I found the following:

User is Bankspower98 and claims 430hp and 667lbft@3200.

There's some roller rocker arms he recommended and I believe they're Comp RPR205 . There's not many that'll fit under our valve covers... and we can't just swap covers because of the throttle body. Plenum spacers existed...
But hood clearance...

That's the truck I'm basing my build plan off of; I miss that thread on FSC.

 

[Mangonesailor]

I made a word doc from the beginning to page 257 of info and had to stop (which was into around 2017's info, so nothing decent I have is still around). Here's some more I have

Found the roller tip rockers from comp:

PN: 1411-16 and they fit under stock covers

Studs recommended: ARP 135-7102

Use poly locks.

You'll have to get the heads to a machine shop to fit the new studs (Old are pressed in? upgrade is threaded?

FYI, since this is a 99 truck the pushrods are 3/8" from the factory. 96/97 had 5/16"

Lunati cam that's recommended: 20010720 but will need the valve guides machined.

Injector info I've kept:



1986-’93: 22 lb/hr (43.5 psi)
1994-’96: 24 lb/hr (43.5 psi)
1990-’92 ZR-1: 20 lb/hr primary, 20 lb/hr secondary (2 per cylinder) (43.5 psi)
1993-’95 ZR-1: 20 lb/hr primary, 20 lb/hr secondary (2 per cylinder) (43.5 psi) (redesigned for ethanol resistance)
1997-’98 LS1: 28 lb/hr (58 psi) (maro/fbird 98 only) (Use L29 clips?)
1999-’00 LS1: 26 lb/hr
2001-’04 LS1/LS6: 28 lb/hr PN 0280155931 (What I use and have injector data for use with HPtuners)

CADILLAC CTS 2004-2005

CHEVROLET CAMARO 2001-2002

CHEVROLET CORVETTE 2001-2004

PONTIAC FIREBIRD 2001-2002

PONTIAC GTO 2004


2005-up LS2: 33 lb/hr
2006-up LS7: 39 lb/hr
2008-up LS3: 41 lb/hr

LS1/LS6 engines all came equipped with Delphi EV1 injectors.
Different p/n's have different lb/hr rated injectors

12533952, 12482704, 12561462 are rated 28.6lb/hr @ 58psi.
12456154, 12555894 are rated 26.2lb/hr @ 58psi.


BSFC: .42 FACTORY

4bar = 58.8psi (Factory pressure)

19lbm/hr at 3bar is 22.01 @ 4bar

Head flow data:

The exhaust port is not inferior for a small block. From what I have seen, the stock Vortec 454 head's exhaust port flows around 145cfm @ .500" (max these engines will see). That is about what a stock cast iron 882 or 441 casting (good GM casting). The L31 small block Vortecs are in the 150's and the Sportsman II's are in the 160~165cfm range at .500". The reason that L29 big block Vortec's exhaust port is inferior for this motor is two fold: 140~150cfm may work for a 350, but not a 454. Heck even on a big inch street small block like a 427, would not recommend the Sportsman II's they'd say to go with the Motown 220's which flow about 190 on the exhaust. So a 454 is going to need at least that. Secondly with a 240 intake at .500" and this miserable 140~145 exhaust, you have a 60% exhaust to intake flow ratio .... no debate, this sucks.

 

[L29Sub]

By the time one professionally rebuilds a 454, using quality components, fitted nicely (rare) the investment will rival a GM performance crate motor.
A crate motor that's maintained will outlast the truck. A poorly fitted engine will empty your wallet and never be useful.
Either way, there will be major outflows and an idea of actual costs to rebuild cannot be figured until the engine is out and carefully torn down. Mark everyhing for placement. Mic it up and ask a quality machine shop to estimate. My guess is that you'll find out why crate motors are so popular. And don't forget the other parts to complete the long block.. Belts, tensioner, water pump, new hoses, O2 sensors (if you go FI?), under plenum harness, fuel injectors, fuel pressure regulator, filters, fuel flex lines, spark plugs, distributor, plug wires, new heater diverter valves (plastic crap), engine oil cooler lines, motor and transmission mounts...ad infinitum.
Now if you go with a 650 Quadrajet, you can buy a carb and manifold (Holly Warrior Vortec) for less than the cost of the new injectors. 650 Quadrajet is good for 500 plus HP. Easy 500. The carb would be ideal with the manual conversion. If keeping the 4l80 (good idea) the factory FI and electronics are sorta required. Or stand alone TCM will work. The only con to carb is cold start characteristics. This isn't a crises. The fuel mileage is very close with both systems. And the cost and futzing around with programming and reprogramming is avoided.
When shopping for parts, remember to stay with Vortec only. '96 thru '99 BB heads, gaskets, valve train, cam drive, and intakes don't interchange with TBI or older BB 454. Never mix heads or head gaskets.
Now git'rdone!


Sent from my SM-G965U using Tapatalk

 

[Mangonesailor]

Oh yeah, if you're going to go carb, ditch the OEM timing set (and stay away from it) becuase 6* of timing retard is built in. Go with an aftermarket double roller with adjustment.

 

[Mangonesailor]

That's the truck I'm basing my build plan off of; I miss that thread on FSC.

Here's the post I made about his truck back when the FSC thread was still "full sized"

 

[badco]

Want rpm to go with torque and gain reliability? Use the 366 steel crank, buy set of h beam rods, lightweight factory design dome pistons, put it all in 454 block and make the best factory production bbc gm had.....427. Use a set of 292 402 heads that are big valve semi closed chamber and have 10.1-10.5;1

 

[badco]

If you know what stock parts to look for the only big expense is the pistons and rods in any build. Stay away from the cheap aftermarket cranks, the 4340 ones only thing worth buying

 

[badco]

I made a word doc from the beginning to page 257 of info and had to stop (which was into around 2017's info, so nothing decent I have is still around). Here's some more I have

Found the roller tip rockers from comp:

PN: 1411-16 and they fit under stock covers

Studs recommended: ARP 135-7102

Use poly locks.

You'll have to get the heads to a machine shop to fit the new studs (Old are pressed in? upgrade is threaded?

FYI, since this is a 99 truck the pushrods are 3/8" from the factory. 96/97 had 5/16"

Lunati cam that's recommended: 20010720 but will need the valve guides machined.

Injector info I've kept:



1986-’93: 22 lb/hr (43.5 psi)
1994-’96: 24 lb/hr (43.5 psi)
1990-’92 ZR-1: 20 lb/hr primary, 20 lb/hr secondary (2 per cylinder) (43.5 psi)
1993-’95 ZR-1: 20 lb/hr primary, 20 lb/hr secondary (2 per cylinder) (43.5 psi) (redesigned for ethanol resistance)
1997-’98 LS1: 28 lb/hr (58 psi) (maro/fbird 98 only) (Use L29 clips?)
1999-’00 LS1: 26 lb/hr
2001-’04 LS1/LS6: 28 lb/hr PN 0280155931 (What I use and have injector data for use with HPtuners)

CADILLAC CTS 2004-2005

CHEVROLET CAMARO 2001-2002

CHEVROLET CORVETTE 2001-2004

PONTIAC FIREBIRD 2001-2002

PONTIAC GTO 2004


2005-up LS2: 33 lb/hr
2006-up LS7: 39 lb/hr
2008-up LS3: 41 lb/hr

LS1/LS6 engines all came equipped with Delphi EV1 injectors.
Different p/n's have different lb/hr rated injectors

12533952, 12482704, 12561462 are rated 28.6lb/hr @ 58psi.
12456154, 12555894 are rated 26.2lb/hr @ 58psi.


BSFC: .42 FACTORY

4bar = 58.8psi (Factory pressure)

19lbm/hr at 3bar is 22.01 @ 4bar

Head flow data:

The exhaust port is not inferior for a small block. From what I have seen, the stock Vortec 454 head's exhaust port flows around 145cfm @ .500" (max these engines will see). That is about what a stock cast iron 882 or 441 casting (good GM casting). The L31 small block Vortecs are in the 150's and the Sportsman II's are in the 160~165cfm range at .500". The reason that L29 big block Vortec's exhaust port is inferior for this motor is two fold: 140~150cfm may work for a 350, but not a 454. Heck even on a big inch street small block like a 427, would not recommend the Sportsman II's they'd say to go with the Motown 220's which flow about 190 on the exhaust. So a 454 is going to need at least that. Secondly with a 240 intake at .500" and this miserable 140~145 exhaust, you have a 60% exhaust to intake flow ratio .... no debate, this sucks.

Exhaust is fine on peanut port heads.... if the intake doesn't even outflow a 283 head why worry about exhaust! All bbc are screw in studs or bolts, the vortec need tapped to 7/16 because the use a funky non adjustable bolt. The vortec bbc flows more than 150 but cant remember exactly what it was. About all the good sbc heads flow close on exhaust and vortec isnt the best flow but it has real good velocity and there is a ring under to valve job that if you go bigger valves you lose flow and velocity

 

[badco]

Even the mighty ls doesn't flow much, its a velocity design and they are 12* heads compared to 23* on stock sbc

 

[badco]

My 23* sbc heads flow 319cfm at .650 and 234 on exhaust on my lil street blazer