454 replace?

tforbes · January 28, 2007

I haven't posted much here, but I have spent many hours looking around and reading. Been working on GM products all my life and have enjoyed most of it. I am now in a quandry, my 1996 1 ton 4x4 has a blown 454. I believe the crank bearings failed. I have not had it apart yet, but all signs, symptoms and the history of the 1996 7.4 vortec lead to that. It has 274,000 miles on the big block. My plan is to replace the motor, since every other working part on the rig is in fantastic shape. Obviously the easiest thing to do is put in a direct replacement, but I have been considering putting an 8.1 in. I tow a lot of heavy equipment and hay and if I am hitched up I am generally over 10,000lbs including trailer weight. I could use all the power and torque I can get. I haven't checked on tranny issues or anything else. Any thoughts or ideas?

95Sierra2500 · January 28, 2007

Get a crate 502 from GM Performance Parts, or just replace the 454. I don't know how easily an 8.1 would drop in, but the 502 is a direct bolt-in.

whitesnake01 · January 29, 2007

Another option: cut your losses and move to a truck with an 8.1 stock engine. Replacing an engine could be a slippery road towards replacing all sorts of things you did not even know needed to be replaced.

95Sierra2500 · January 29, 2007

Another option: cut your losses and move to a truck with an 8.1 stock engine. Replacing an engine could be a slippery road towards replacing all sorts of things you did not even know needed to be replaced.

If you've taken care of the vehicle, then replacing the engine is no big hassle and does not lead to the replacement of other parts. If you've just used and abused it with no regard for maintenance then yes, it's probably time for a new truck. However, the 502 comes with 502 hp and an ungodly amount of torque according to GMPP.

tforbes · January 29, 2007

If you've taken care of the vehicle, then replacing the engine is no big hassle and does not lead to the replacement of other parts. If you've just used and abused it with no regard for maintenance then yes, it's probably time for a new truck. However, the 502 comes with 502 hp and an ungodly amount of torque according to GMPP.

I won't say that I haven't worked my truck hard, but everything has been maintained above all recommendations and I have had no problems and have no signs or symptoms of problems with any other aspect of this truck. I would really enjoy dropping in a 502, but the only 502 I can find that will run on fuel injection is the Ramjet. Which, I would have no problem with, but I wasn't planning on spending 10k on just the motor. I don't mind the idea of buying a 502 and running a carbuerator, but I am afraid of what computer hassles that may bring. I wish I could rip my computer completely out! Oh well. The reasons behind me not just buying a new one. Cost prohibitive to begin with, and I don't want a dually. The only 1 ton 4x4 crew cabs I can find are duallys. And now there is no more 8.1. So I will drop something in my current truck and keep hauling.

95Sierra2500 · January 29, 2007

You can buy just the crate engine 502. It's not the ramjet, it's the one that comes as a long block (block, heads, crank, pistons, cam, valve covers, etc.) and has no intake, water pump, distributor, pulleys, or other accessories. All your stuff (intake included) will bolt on and it SHOULD fire right up. You may want to upgrade to a better distributor if you go that route.

http://www.gmperformanceparts.com/Parts/sh...il.jsp?engine=3

That should take you to the engine you want. Just because it suggest running a carb doesn't mean you can't run fuel injection on it since it's a bare engine.

blockader09 · February 1, 2007

I have a 99 2500 crew cab with a 454 with 76000 on it. I want to swap it for a 350. I would like to sell it. Let me know if you are interested. Chris

tforbes · February 4, 2007

I have a 99 2500 crew cab with a 454 with 76000 on it. I want to swap it for a 350. I would like to sell it. Let me know if you are interested. Chris

Is there anything wrong with it? How much do you want? And what part of the country are you in?

Has anybody heard of the FSB that supposedly came out suggesting transmission problems when crank bearings go bad on the 1996 version of the 7.4 Vortec? It makes sense since the drive angle could change on the crank and flywheel and all the way through the tranny. A friend of mine told me he saw it somewhere and I can't seem to find anything suggesting those problems.