350 to 454 swap questions.

[Tag George]

I doubt it will ever happen but want to know more about it. My 95 cab and chassis crew cab pulls my loaded trailer at low speed fine. But struggles to maintain 55 on nearly flat ground with little wind. It is a 5.7 TBI with a nv4500. I think it has 4.10 gears. I know you guys say my truck does not exist but it is what I have.

1. If i find a 454 I have had one guy say my trans would have to be moved messing with my drive shafts. Is this true it seems wrong to me.?

2. Can I use the same computer and wire harness as my 350? I see when I look around the net some say it depends on the year but I have not found which years they are talking about.


Ok out time for now. Dont even have to to proof read this. Thanks.

 

[DieselCash]

My 6.5 and NV4500 and 4.10 gears has the same problem. Zero to about 50, no problem. Anything over that and small hills finish me off. I am really leaning toward the rear end gears is what is holding me back. I will say I have not yet turned up my pump. I also still want the ATT turbo.

For you I would try different gears also. It has to be a lot cheaper than changing out motors.

 

[THEFERMANATOR]

Pretty sure a 454 bolts right in. The engine mounting pads on the frame did not change for any of the engines. The 4.3L uses an addball mount to mount the V-6 in, but all of the V8's use the same basic mount design. I know the 6.5L drops in directly in place of a 350, and a 454 drops in directly in place of a 6.5. If you were to find a 454 TBI engine, I'm sure you could find somebody to burn a PROM chip to re-use your current ECM with it. As far as the rest, you would have to do some work to fit in the 454 radiator as I believe in 95 the 350 used the smaller 28" radiator core VS the 454's 34" core radiator. It's a doable swap by all accounts, and not hard to do. Myself I owuld freshen up the 350, do a cam swap, clean up the heads, and a few other things and stick with the 350.

 

[Tag George]

I think I already have the Larger radiator. Maybe that is what comes with a cab chassis truck.

 

[Tag George]

I have the 454 now. It is from a 93. So it should have the 93 injectors which run on lower pressure same as the 350 from 93. Since my truck is a 95 with a 350 fuel pump will this still work if I find a stock 454 GM chip for my computer? I know it would not work with the 95 injectors and a 350 pump.

What are my best exhaust options for getting it going before the exhaust shop? It did come with the manifolds.

 

[THEFERMANATOR]

Your current pump should be fine for a 93, but it is always a good idea to upgrade to the 94-95 454 pump as the stock low pressure TBI pump only makes about 13PSI if you dead head it(hook the output straight to a gauge). Find a PROM chip from a 93 454 with the same ECM as yours, swap PROM's, and your good to go.