1991 Sierra 1500 Short Bed V6, question on motor swap?

[TheKid]

Hello guys,

My name is John. Im looking to buy a 1991 GMC Sierra 1500 Shortbed with a V6 motor and 5speed transmission. I want to eventually do a motor swap and put either a V8 305 or V8 350 in place of the current V6. I had a V8 305 1500 sierra truck in the past with a 5speed and i loved it and want another cause i sold it, but I dont know anything about the V6 model and that happens to be to model available to me right now. So my questions are:

1) Is the body on the V6 any different than the V8?
2) Will the future 305 or 350 motor fit right in?
3) Will I need to swap out the current 5 speed transmission or will it bolt right up?
4) Drive shaft?
5) Are the rearend gears the same in the V6 and V8 models?
6) Any suspension conversions need to be done?
If you guys can list anything else that would need to be changed for the conversion so I have a good idea how much work is involved. I have pulled motors before, but im not familiar with th V6 model. Any help would be great guys, thank you.

 

[Molson02536]

Hello guys,

My name is John. Im looking to buy a 1991 GMC Sierra 1500 Shortbed with a V6 motor and 5speed transmission. I want to eventually do a motor swap and put either a V8 305 or V8 350 in place of the current V6. I had a V8 305 1500 sierra truck in the past with a 5speed and i loved it and want another cause i sold it, but I dont know anything about the V6 model and that happens to be to model available to me right now. So my questions are:

1) Is the body on the V6 any different than the V8?
2) Will the future 305 or 350 motor fit right in?
3) Will I need to swap out the current 5 speed transmission or will it bolt right up?
4) Drive shaft?
5) Are the rearend gears the same in the V6 and V8 models?
6) Any suspension conversions need to be done?
If you guys can list anything else that would need to be changed for the conversion so I have a good idea how much work is involved. I have pulled motors before, but im not familiar with th V6 model. Any help would be great guys, thank you.

Swap right in, but your going to also have to swap out the ECM and wire harness for the V8.

Food for though, would it be better for you to swap in a LS engine from the years 1997 to 2007. Note though the years in 2004 LS engines gave more HP.

There are lots of 5.3 litre LS engine in salvage yards with warranty and in most case, you can buy them with engine, transmission and ECM harness and all for just under $1,500.00 and the 4.8 liter LS engine is even cheaper 270 HP and 295 HP on the 2004 and up.

Keep us posed

Molson02536

 

[TheKid]

Swap right in, but your going to also have to swap out the ECM and wire harness for the V8.

Food for though, would it be better for you to swap in a LS engine from the years 1997 to 2007. Note though the years in 2004 LS engines gave more HP.

There are lots of 5.3 litre LS engine in salvage yards with warranty and in most case, you can buy them with engine, transmission and ECM harness and all for just under $1,500.00 and the 4.8 liter LS engine is even cheaper 270 HP and 295 HP on the 2004 and up.

Keep us posed

Molson02536

Hey if your saying that would be a better choice, I may consider it. Do you know if the transmission that is there is the same 5speed that they used for the V8 and would it bolt right up?

 

[Molson02536]

Hey if your saying that would be a better choice, I may consider it. Do you know if the transmission that is there is the same 5speed that they used for the V8 and would it bolt right up?

It should bolt up, I believe they have the same bellhousing pattern that GM has used for years. Everything else your truck has should be fine to handle that amount of horsepower. The only thing you may consider is getting a locker type rear end if you do not already have one.

Keep us posted

Molson02536