Stock Gen V 454 upgrades?

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jkirk1992

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Hi there all! Looking for some advice here. I’ve got a 92 K2500 with a 454, bone stock pickup. I’m interested in getting just a little bit more power out of that boat anchor under the hood without completely killing my wallet. For now I’d like to get a slightly more aggressive cam within the stock piston/valve clearance, any recommendations on lift/duration? And I’ll maybe look at replacing that worn out TBI. I’m seriously considering swapping from TBI to carb. I just use the pickup as an extra vehicle now, but being in MT temps do get low and I use it when weather gets crappy. That’s the only concern about going to a carb, but I did daily a ‘71 K20 with a 454/4bl carb for a while so I don’t mind harder cold starts. Any and all advice is appreciated.
Thanks!
J.
 

jkirk1992

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I'm in the exact same boat with an 89 K3500... im gonna go have a seat in the back row here and see if i can learn something.
4L80E or TH400?
4l80E. Only thing I worry about it having to deal with a stand alone harness for the trans and making sure everything still works… with that I might consider something other than a carb. I’m open to any and all suggestions, just want something better than the factory TBI.
 

AK 99

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Hi there all! Looking for some advice here. I’ve got a 92 K2500 with a 454, bone stock pickup. I’m interested in getting just a little bit more power out of that boat anchor under the hood without completely killing my wallet. For now I’d like to get a slightly more aggressive cam within the stock piston/valve clearance, any recommendations on lift/duration? And I’ll maybe look at replacing that worn out TBI. I’m seriously considering swapping from TBI to carb. I just use the pickup as an extra vehicle now, but being in MT temps do get low and I use it when weather gets crappy. That’s the only concern about going to a carb, but I did daily a ‘71 K20 with a 454/4bl carb for a while so I don’t mind harder cold starts. Any and all advice is appreciated.
Thanks!
J.

There's a bunch of complications with trying to do just a simple and mild hop up of a '91-'95 454. For just a simple cam swap, you are limited to very mild lift due to valve guide clearance. The stock valve springs are barely adequate with a stock cam, so they must be upgraded as well. Finding ones that work well with your cam AND clear the valve guides AND fit the stock retainers is tedious. Plus you will have unstable factory valve rotators on the exhaust and possibly the intake valves as well. Comp Cams sells "rotator eliminators" that will take their place and let you run a spring with a more normal installed height, but the eliminators will need minor machining to clear the intake valve guides. Then there's the spindly 5/16" pushrods that will need replaced with 3/8" pushrods, and matching guide plates for the 3/8" pushrods. Then you will also need ARP conversion studs to make your rockers adjustable so you can adjust valve lash with the replacement cam. You will also need a new quality timing set to replace the factory set with nylon teeth on the cam sprocket. So after all that, you still have a very mild cam with stock peanut port heads and low compression.

I'm in the exact same boat with an 89 K3500... im gonna go have a seat in the back row here and see if i can learn something.
4L80E or TH400?

You will have an easier time due to having an older MarkIV 454. Just pick a cam, get the matching springs, pushrods and guide plates and source a used set of 049 or 781 heads to have redone. It will really liven it up and it won't cost a lot in the grand scheme of things. Although there's still TBI tuning to deal with if you don't swap to a carb.
 

LC2NLS6

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TBI era is literally the worst starting point to upgrade, as everything but the 4 bolt block needs upgrading. Tiny heads, no compression, poor fuel injection, computer controlled ignition timing, terrible intake manifold, enough sensors required to make it annoying to wire up.

My 93 K2500 454 experience:
I did a comp cam SK11-302-4 212/218 and 911 springs upgrade, and I bent the pushrods. I thought it was a wiped cam, but it was just normal wear on the lifters on breakiin. Ran awesome. I have the cam and lifters in a box still. But too much lash. So I pulled it out and another cam. Wiped that cam for real on startup. So I pulled the engine and bumped the compression up with dome pistons and a comp 215/215 magnum roller cam to get away from flat tappets. Had to remove the rotators, I think that was my problem. The springs had the right installed height I think 1.9xx?, but I never verified the pressure, so I may have had too much spring for the flat tappet versions or it was bottoming out.

For injection, I went with Holley Sniper and hyperspark ignition. Sure it works, but lots of people complain about it but I suspect it is their lack of following the wiring instructions. I'd go with another Holley than the sniper if had to go that route again to get the Holley to also control the transmission, but those will run $3000-4000 by the time you buy everything. Right now I have the Holley for fuel/ignition and the stock computer hooked up to control the trans.

I like the 215/215 roller and stock gen V peanut ports (removed rotators and installed spacer/locaters and custom short poly locks to have an adjustable valve train with full roller rockers to fit under the stock valve covers). It is all done by 5000 rpm and starts falling off. Has tons of torque off idle. If I shift at 5000 1-2 it barks the rears. The factory shift point of 4200 or so is fine 99% of the time.

 
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matthews454ss

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I had a comp cams XE256 cam and spring kit in my stock 1990 (gen4) 454. I think its 480ish lift. That cam would PROBABLY have enough piston to valve clearance for the Gen5. I also switch to a carb manifold with fitech. It made 280 HP to the wheels.
 

jkirk1992

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There's a bunch of complications with trying to do just a simple and mild hop up of a '91-'95 454. For just a simple cam swap, you are limited to very mild lift due to valve guide clearance. The stock valve springs are barely adequate with a stock cam, so they must be upgraded as well. Finding ones that work well with your cam AND clear the valve guides AND fit the stock retainers is tedious. Plus you will have unstable factory valve rotators on the exhaust and possibly the intake valves as well. Comp Cams sells "rotator eliminators" that will take their place and let you run a spring with a more normal installed height, but the eliminators will need minor machining to clear the intake valve guides. Then there's the spindly 5/16" pushrods that will need replaced with 3/8" pushrods, and matching guide plates for the 3/8" pushrods. Then you will also need ARP conversion studs to make your rockers adjustable so you can adjust valve lash with the replacement cam. You will also need a new quality timing set to replace the factory set with nylon teeth on the cam sprocket. So after all that, you still have a very mild cam with stock peanut port heads and low compression.



You will have an easier time due to having an older MarkIV 454. Just pick a cam, get the matching springs, pushrods and guide plates and source a used set of 049 or 781 heads to have redone. It will really liven it up and it won't cost a lot in the grand scheme of things. Although there's still TBI tuning to deal with if you don't swap to a carb.
Hmm, sounds like it is complicated for a mild hop up. Big thank you for all the info! With all of that in mind, maybe I should look into a cyl head swap with a new valve train? I've been looking into that after reading your reply. That way I can up the compression and worry a little less about making the stock clearance, maybe even get rid of those peanut ports. Thoughts?
 

AK 99

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Hmm, sounds like it is complicated for a mild hop up. Big thank you for all the info! With all of that in mind, maybe I should look into a cyl head swap with a new valve train? I've been looking into that after reading your reply. That way I can up the compression and worry a little less about making the stock clearance, maybe even get rid of those peanut ports. Thoughts?

For a head swap, you will be looking at aftermarket heads (most, if not all, are cast to seal the coolant passages on all generations) or a set of heads from a '96-'00 Vortec 454. With the late model heads, you still have to deal with the conversion studs and whatnot, but the heads at least have much greater potential than the older peanut ports.

I believe Edelbrock still offers a set of heads that are angle milled to get the compression up a bit.

You also can upgrade to a roller cam fairly easily. Your block should have the provision to run a cam retention plate like what was used on the '96-'00. You will still need to run the aftermarket link-bar type lifters (Howard's was the best deal last time I was shopping) but you won't have to mess with cam button adjustment or finding a sturdy replacement for the oddball gen5 timing cover.
 
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