want to replace 1990 4.3omc with 1999 4.3 truck engine

[barnstormerj]

Realizing that the 99 4.3l has a different block, as per the vortec heads, intake , and the balance shaft. How much difficulty will I have by using the newer engine. I know I will have to hunt up a special intake manifold, and use the dampener that came with the newer engine, will the flywheel be balanced correctly from the older engine to use on the newer one, as I think the newer one was an automatic transmission engine. Also, will have to use an electric fuel pump? and what about the belt system? serpentine on newer engine, will I have to convert pulleys? or stay with the water pump, accessories , and pulleys from older engine, and modify the timing cover? Just trying to get more ideas about the swap. I have done some swaps I have had lots of fun with, and some I had quite a challenge with. Please give me input if possible.

 

[barnstormerj]

Re: want to replace 1990 4.3omc with 1999 4.3 truck engine

reason for replacing is bad engine, and availability of newer engines.

 

[jc turtle]

Re: want to replace 1990 4.3omc with 1999 4.3 truck engine

Hi, I think you could make the later engine work. For example, the water pump is the same for a 1990 S10 Blazer and a 1999
S10 Blazer, whick is also the same for a 2000 Chevy pickup with a 350 R motor. Many of the parts are the same between v6 and v8,
so you could probably use the pulleys you have. You could leave the crank sensor in the timing cover to seal the hole. I put a 1999
350 cmotor in place of a 1988 350 in my son's boat. I did have to use an electrical fuel pump. I bought a manifold on ebay for the
vortec v8. I am sure there is a place to buy a v6 manifold. You would have to see if the exhaust manifold gaskets are the same
for a 1990 and a 1999. The Vortec engine has more ponies, so that's always good. Sounds like it is doable. Good luck, John