I have a 96 k2500 suburban with the 454 motor. I have a superchip and a k&n intake and am soon to have custom 3" exhaust, but I am looking for much more power. If I were to pull the block and completely build the motor while still utilizing the current fuel injection system (upgraded injectors, etc), what kind of power can I expect to make?

 

they can make hhuge power depending on the money you throw at it. ditch the fuel injection and go carb if your wanting to make a real performance motor.

 

If you want to keep the stock bottom end, also consider a nice set of oval port closed chamber heads with some good port work Make sure you upgrade the intake manifold too as you have a "peanut port" intake which won't match up to the new heads. It's a nice breath of fresh air to hear about someone wanting to build one of these beasts up

 

Is that still in the TBI injection era? If so, that is gonna be the limiting factor awfully quickly.

Otherwise, yeah, the other fella's suggestions, especially a top-end swap to some nice oval ports with a matched intake and a street cam to boot, would make a pretty torquey big-block for the street.

 

No, 96 was the first year that they ditched the TBI system. Are there any companies you recommend as far as pistons, rods, cams, etc?

 

I've worked on a couple of those that were built nicely. With a set of ported heads, camshaft, ported intake, headers, cat back, cold air intake, etc., it will make 400+fwhp and around 500fwtq. The only problem is how much you'll spend to get it there unless you do most of it yourself. Make sure it's tuned for what you have done though.

 

You can easily run a set of mark IV heads on a mark V block. The only difference is the water jacket holes are shaped differently. They make adaptor inserts that will allow you to do so. Or at least they used to 10 years ago when I built mine

 

heads and compression really kill them motors

 

As I recall the Vortec 454's in '96 were an evolutionary design. That should be first year OBD2. If so, the heads we have seen come through here are an oval port design. Quite a better design than the years prior. GM went back to an oval port intake runner and smaller combustion chambers. The heads respond to some mild port and valve work. The cam should be hyd. roller. Choose a camshaft wisely. Keep is small if you don't have much stall in the coverter.

Good luck,

Richard

 

My knowledge of the Gen VI L29 style Vortec 454 heads are that they are of a large oval design with basically 100cc combustion chambers. Like Richard mentioned, I would stay with a reasonably small camshaft unless you were to convert the heads from the net-lash rocker set-up that they were equipped with. You can convert the heads from the net-lash configuration that the Gen V & VI’s use by drilling and tapping the factory 3/8” rocker bolt holes out to the 7/16” bolt holes that the Mark IV’s used. When doing so you will then have to use the adjustable rockers, pushrod guide plates and pushrods from the Mark IV. You could also use a conversion stud arrangement, but there again if you were to do so, you would need to limit your cam size as the conversion studs will not handle too much spring pressure before failing. They are actually pretty good heads and can be quite a performance booster to most of the smog era big-blocks that originally came with either the peanut style ports or 119cc heads that resulted in them having 8.5:1 compression, in most cases they were saddled with both the small heads and low compression. They respond well to adding the larger 2.19/1.88 valves in place of the stock 2.07 / 1.72 pieces, yet may be unnecessary in a fairly low RPM configuration. The L29 intake is not that bad and the injectors are of the same type as the L98 small-block, so there are plenty of options for larger injectors. The intake consisting of a lower and upper configuration lends to access when porting is deemed necessary. I would concentrate on a healthy lower RPM set-up as the PCM in the ’96 to ’98 models as everyone knows does not allow anything over 5800rpm anyways. Bottom end components can be purchased and assembled as you would with any traditional big-block, the only major difference being that the L29 454 has a one-piece seal crank and as such has particular balance requirements.