454 into a 1/2 ton What am I in for?

[77c10diesel]

I have a 77 1/2 ton long bed that originally had a 350 and I converted it to a 350 Olds Diesel. I no longer need the small diesel, I have a Cummins. So, I found an 83 3/4 ton with a 454 that I want to use as a donor. Is this a straight forward swap?
I have done many engine swaps, engine conversions, rebuilds etc.(I am a Mechanic by trade) What I need to know is if I will run into any issues with the frame mounts, or any other parts of the 83 454 not wanting to work in the 77 1/2 ton frame.
The 83 is a complete truck so all the parts are there. It only has 59,000 original miles on it.
Thanks for any help you can give.
Scott

[Da67goatman]

Me buddy has a 454 in place of the 400sbc in his 79 4x4 and he had to get a short fuel pump because the normal one hit the frame.

[choptop]

The main thing that comes to mind is if the trans behind the deisel is the BOP or chevrolet pattern. Thats first, the only other thing is you may have to invest in a bigblock radiator but the one running the deisel should be large enough, just have to make sure the water outlets are in the same place. I dont know of any other issues youd have. I dont know if the 83 has the electronic spark control and electronic carb, but if it does, now is the right time to do away with them. I swapped a 454 out of a 78 to an 81 that had a small block and the only issure I had was the headers, but that was going from a 4wd to a 2wd. I used all the accessories and engine mounts off of the 454 truck. I already had a 4 core radiator in the 81.

[77c10diesel]

The 83 that I am going to get is a complete truck, it has trans, radiator, everything.
That's good to know about the fuel pump and the spark control.
Anything else I need to know?

[fitz]

Does the 83 have hydro boost brakes? If so you will have to deal with the power steering pump brackets.

[VileZambonie]

Big blocks fit in the half tons no problem.

[TxFiddler]

Big blocks fit in the half tons no problem.

I will definitely second that!

[fitz]

Big blocks fit in the half tons no problem.

I will definitely second that!

Fiddler,
What motor mounts did you use for your swap?

[TxFiddler]

Fitz,
I used the same mounts from the 350.  All I did was put some new Energy Suspension inserts in them after they were powder coated.  I do want to caution you though.  If you replace the inserts with Energy Suspension, the mounts are a beast to get lined up but it WILL eventually just fall into place.  I also have plenty of room to remove the pan to change the gasket or rear main seal if needed.
Fidd

[fitz]

Thanks,
Any header clearance problems using the SB mounts.

77C10, I'm not trying to take over your post, but I'm planning a SB to BB swap myself so I figured these questions will help both of us.
 Fitz.
 

[TxFiddler]

I used Doug's Headers (Pertronics) that are made for a big block in a 73-87.  No clearance issues at all.
Fidd

[77c10diesel]

Thanks for all the input guys. The truck I had a line on got taken away in a package deal to someone else. So, I will either look for another one, or try to get the Diesel going.
This truck is a fun only truck and so I am in no hurry, I have my Cummins for daily driving.
I think a 77 with a 350 Diesel would be cool, but a 454 would have way more power and be fun to drive.