Engine swap from 4.3 v6 to 5.3 v8

98sierra5.3

Original poster
Member
Mar 7, 2016
3
Arizona
Has anyone done this swap on older gm trucks like the 98 Sierra if so I need to know if I can keep the same fuel pump and radiator
 

northcreek

Member
Jan 15, 2012
3,320
WNY
If your 4.3 was CPI you might be ok on the FP, if it's TB injection it won't be enough psi.
As for the radiator, you will be going from a iron engine to an aluminum one, this means that now, any overheating will be catastrophic. I would want a good sized aluminum radiator to match...Mike.
fwiw Your old FP had a fuel return system and I believe the 5.3's did away with that so that may make the interface a little tricky.
 
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98sierra5.3

Original poster
Member
Mar 7, 2016
3
Arizona
If your 4.3 was CPI you might be ok on the FP, if it's TB injection it won't be enough psi.
As for the radiator, you will be going from a iron engine to an aluminum one, this means that now, any overheating will be catastrophic. I would want a good sized aluminum radiator to match...Mike.
fwiw Your old FP had a fuel return system and I believe the 5.3's did away with that so that may make the interface a little tricky.
Well with the block I chose not to get the all aluminum I have the cast iron block and I think I have the cpi...also what will Ihave to do about the harness.
 

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