2003 Silverado 4.3 to 4.8 or 5.3 engine swap

[hartinclay]

How hard would it be to swap the 4.3 out of my 2003 Silverado for a 4.8 or 5.3 v8 engine. I plan on finding an engine out of the same year model truck or newer. I know i need the motor mounts and the fuel pump but what else do i need such as hoses, wiring, ac stuff etc. and would i need to get a computer from nelson performance and have mine reflashed ur information would be greatly needed and about how much will all this cost

[ducky]

http://www.ls1truck.com/forums/v8-co...wap-guide.html

http://www.ls1truck.com/forums/v8-co...5-my-swap.html

http://www.ls1truck.com/forums/pics-...cont-pics.html

The only difference in the above two links is that your throttle body is DBW, so you need to make sure you get an 03 and up V8 harness

[hartinclay]

Are you sure im dbw because i read somewhere that all 4.3 v6s are dbc, even the newer ones. Also what do I have to do about the fuel lines and pump. Will the radiator in my truck work as well.
I can get a 5.3 V8 with 40 thousand to 50 thousand miles for 800 to 900 dollars and anything else i need off the truck is this a good price

[TDK08]

I guess the quick way to find out is to check your throttle body to see if it is DBW or DBC...

DBC will have two cables going to the throttle.

[ducky]

Are you sure im dbw because i read somewhere that all 4.3 v6s are dbc, even the newer ones. Also what do I have to do about the fuel lines and pump. Will the radiator in my truck work as well.
I can get a 5.3 V8 with 40 thousand to 50 thousand miles for 800 to 900 dollars and anything else i need off the truck is this a good price

I guess the quick way to find out is to check your throttle body to see if it is DBW or DBC...

DBC will have two cables going to the throttle.

What he said. Just pop your head and check. And as for fuel lines. I bought two foot long steel braided fuel lines from summit as well as two male fittings and two female fittings. I cut the ends off the stock fuel lines and put the fittings on and then attatched everything. Just make sure you dont cut the stock fuel lines too short. I almost did

[GasGuzzler]

Never heard of a DBW 4.3 V-6 but weird things happen in truck land.

[hartinclay]

Its drive by cable, I can get a throttle body off of ebay thats dbc for 80 bucks, I am wondering if this will screw up anything on the wiring harness since 03 and up v8s are dbw. I plan on just bolting on the dbc throttle body and hope that it all works

[skeet]

you'll be fine, plus your dbc tb will work also

[hartinclay]

So you are saying the throttle body off of my v6 will work on the v8

[cjcalhoun]

all 4.3 are drive by cable i also have a 03 short step reg cab also i was wondering about this to and also is the harness plug and play or do i have to change wires in the fuse box i can do anything with a carb but not so much with electical i understand the swap is straight forward just unshure of electrical also is a factory locker a good rearend i swaped one in my truck had the same gears 3:41 and disc brakes out of a suburban