V/6 to V/8

[buffle]

I just bought a 1987 FI V/6 truck. Will it be a nightmare to V/8 it. It has a 400 turbo in it now.

[86c20]

i dont see why it would be. you would need the v8 cpu and the correct throttle body for a v8. if it has a 400 you are fine. but i think wwe need more info here. what v8? 305 350 454? i do know one thing for sure you will need a bigger rad unless its a 305. imho a 305 is a wast of time. also if there is no emissions in your area you could just but a carb on it and call it a day.

[andrewmp6]

If it was me i would go 350 and a over drive trans like a 700r4 or maybe the 2004r which is what the g body had.Or if you got the cash a ls1 4l60 is a nice combo too.

[remist17]

I just completed a 87 V6 to a 383. I also have the 400 trans option.

The motor mounts can be a pain in the butt. The V6 will not work on the V8 model. Also note that just any V8 motor mount bracket will not work on the truck or at least it didnt on mine.

If your going carb then the CPU is not needed, but since 87 was the first year to have teh 400 kick down in the computer a switch is needed. Bought it have not installed it yet.

[x ReAcT x]

Originally Posted by remist17

I just completed a 87 V6 to a 383. I also have the 400 trans option.

The motor mounts can be a pain in the butt. The V6 will not work on the V8 model. Also note that just any V8 motor mount bracket will not work on the truck or at least it didnt on mine.

If your going carb then the CPU is not needed, but since 87 was the first year to have teh 400 kick down in the computer a switch is needed. Bought it have not installed it yet.

Im about to convert an 86 v6 to a RAMJET 350 v8, from what it sounds like, the motor mounts are going to be a huge problem, is that true?

[rollinhard]

In 87 the trans was changed to a 3L80hd essentially a t400 with long 28 spline output shaft. Just an fyi. And the motor mounts arnt a big issue. You can use the ones off the v6 but have to adjust them as far as I can remember. Did this swap many years ago. But I went carb'd.
Curtis

[Chevylongbed]

Originally Posted by 86c20

i dont see why it would be. you would need the v8 cpu and the correct throttle body for a v8. if it has a 400 you are fine. but i think wwe need more info here. what v8? 305 350 454? i do know one thing for sure you will need a bigger rad unless its a 305. imho a 305 is a wast of time. also if there is no emissions in your area you could just but a carb on it and call it a day.

How about if i want to have 454 engine, what should i change?? and what is the best manual tranny for it??

[rollinhard]

What r your plans for the truck and that would determine quite abit.

[remist17]

Originally Posted by rollinhard

In 87 the trans was changed to a 3L80hd essentially a t400 with long 28 spline output shaft. Just an fyi. And the motor mounts arnt a big issue. You can use the ones off the v6 but have to adjust them as far as I can remember. Did this swap many years ago. But I went carb'd.
Curtis

This maybe true on most trucks. The one I have the 6 cyl mounts will not work. These are not the same as the 8 cyl and unless you want yo do some fabrication to make these work it is easier to find the entire set up in a junk yard.

Take measurmenets of the frame as these are also different from model to model. Again this is from my experience and headaches. If you want more informtion on what I went through PM me.

[rollinhard]

Ya your right. I looked in lmc and it shows small blocks from 73-87 are the same. V6 are 2 different part #s and I6. Is the same as small block. Then big block is different again.