4.3 to 350

i have a 1990 g10 van that has a 4.3tbi in it and i want to put in a 350tbi and i need to know want what all is involed i already talked to a few people and the shop i am getting the 350 from he said the ecu and the trany will all work but i need to know about the motor mouts if they are the same my chevy friend said everything would work just the same and i just want to do some more checking befor i do it

i have a 1990 g10 van that has a 4.3tbi in it and i want to put in a 350tbi and i need to know want what all is involed i already talked to a few people and the shop i am getting the 350 from he said the ecu and the trany will all work but i need to know about the motor mouts if they are the same my chevy friend said everything would work just the same and i just want to do some more checking befor i do it

Lot of things on a 4.3 truck will be lighter and need changed for a 350 engine.
Check a salvage yard in terchange.
Mt mounts brackets may need changed.
Ehaust system changed.
Bigger rad and fan shroud.
Computer prom change.
And the 4.3 transmission will be weak behind a 350 engine.
4.3 front springs/torson bars and front end and brakes and tires will be light for the extra 350 weight.
Lisense and title will need to be changed for state registration and insurance changed for bigger engine.

well my van is a 1/2 ton and i was told the that the only thing i needed to change is the motor because my van had the options for a 305 in it and that a 4.3 is the same as a 350 just 2 cylinders shoter i can see have to change the mounts but with it being tbi to tbi i was told it would be ok

The wiring is the same and the computer will compesate for the 350.he engine mount may have to moved forward.My father has done one to a Chevy truck and the owner never had to go to the DVM.

yeah thats the same things i have been told by many people! my buddy at work said that the other guy did not know what he was talkin about but its cool becasue i got a friend who has done this to a few trucks and he said the same things and is going to be giving me a hand when i do the change. but still thank u for the insight.