cb1

I have a 95 C1500 with a 5.7. It has 272K miles on it. I can get a 7.4 with 53K miles on it. What all would need to be done if I was to swap it out?
I'm thinking the fuel pump, exhaust and maybe the radiator. What about the engine computer and what needs to be done to the tranny?

Thanks for the help.

89silverado283

ok well if you a have a manual tranny you should be able to change the bell houseing and as far as that goes,auto trannys are either big block or smalls block, and fuel pump should be fine to not change it should pump enough gas, if you can not do high way driving then change the pump... the radiator should be fine,, hell i have a 1980 350 and i had a bigger radiator then my friend and his 1974 chevy 454, exhaust just some big block headers and thats about it, so you got the tranny and the exhuast, i had a 4.3l v6 computer on my 350 v8 so i dont think you need to change it... hopefuly this helps you for the hole switch MAYBE 500$ thats if you do it your self

89silverado283

k so i lied about the tranny thing, i just went and looked at my cuasins 454 that he has in the bed of his truck his 454 is from 75-87, this could make a differents but his older 454 will bolt to what ever trany you have thats small block,,,,

mudmaniac

Is the 7.4 a throttle body set up? If so the computer may still work, if not you would need to change the electronics.

cb1

It's out of a 93 suburban, so I'm guessing yes it is a TBI

mudmaniac

Cool, I think the electronics will work fine, I used to run 454 injectors with no problem on my 383.

RPegram

You'll probably need to get the gas tank along with it. Yours alone is not going to be big enough. A big block can suck some gas fast. You can look for a 30%-50% drop in fuel mileage. Other than using a lot more gas, you won't see big changes in anything else. Don't put it in if you think this will give you a mean machine. This engine was put in the other truck for pulling not smoking the wheels. If you want HP, then you will spend more on this engine than you will the 350. If you do go through with the swap, you will need the radiator, hoses and as much of exhaust as you can get. Also make sure both are either 4X4 or 4X2. This makes a difference with oil filters, housing and such. Check for engine oil cooling lines. Your truck may or may not be set up for these. I would plan on getting everything that has to do with engine that is not bolted to it. At least both trucks use same pressure fuel pumps. Oh, and don't forget that extra gas tank, you will need it.