Adding a 6.5 turbo to a 6.2

[kconnair]

My 84 3/4 ton 2 wheel drive Suburban has a van model J code 6.2. Automatic (turbo 400) No A/C. The engine is an unknown year 6.2 - might have been a Goodwrench replacement at one time, since one of the valve covers is from a replacement engine. Obviously not the original engine in the truck anyway. So, since it was a van engine, it has the short injectors. I already have (truck style - not van) the Passenger manifold, cross over, turbo, turbo intake, air box, oil lines, etc. I know I will have to come up with a manual boost regulator for the wastegate.

The frame will be in the way of the down pipe - obviously.

Here is the question:

Exhaust routing and sizes?

3"?

outside the frame, and back inside?
outside the frame and stay there?
between the block, frame and firewall and then follow stock exhaust routing?
Dimple/cut the firewall for clearance and follow stock exhaust routing?

Rotate the turbo, or add a wedge shaped spacer?
Flip the turbo around to the front?

Combinations of any of the above?

Ideas?

Thanks,

Kevin.

[NH2112]

Is it a center-mounted van turbo, or a side-mounted pickup/Suburban model? Going by my experience with a 6.5l turbo in my 85 C1500, I think 3" outside the frame and staying there is the best idea. There's just not enough room between the frame and tranny for a 3". The only "maybe" in this idea is whether you can make a 90 degree downpipe that will clear the top of the framerail, but I think it can be done. I'm assuming that you have an automatic, and in that case I'd find a 6.5l TD driver's side exhaust manifold so you can use a 2 1/2" crossover pipe. I had to use the 6.2l manifold and modify the crossover in order to clear the slave cylinder.

[kconnair]

Thanks for the reply.

The conversion parts I have accumulated are all for the "C/K" truck chassis, not a "G" - Van. Truck is a 2 wheel drive automatic - turbo 400.

The outside the frame rails exhaust seems like it might end up being the best solution, but I am not yet sure. -just looking for additional ideas I have not thought of already.

Thanks, :)

Kevin.

[kconnair]

In addition to putting on the turbo, I was planning on pulling the engine to replace the rear main seal too. Should I replace the head gaskets at the same time? Fel Pro or Victor?


Recommendations?

Thanks,

Kevin.

[NH2112]

I wouldn't pull the engine just to replace the rear main. However, if you need (or want) to replace the head gaskets it's much easier to do it out of the vehicle. Depending on what year the replacement engine is it could have the 1-piece rear main, and you have to pull the tranny to do that job. If you don't end up pulling the engine then sliding the tranny back, replacing the main, and bolting the tranny up shouldn't take much more than an hour or so. Replacing the old-style rear main (2-piece) means the oil pan has to be dropped, and after dropping one 2WD oil pan I decided the next time I have to do it I'm just unbolting the front end and moving it out of the way instead of unbolting and raising the engine.

If you end up pulling the engine, you might want to replace the water pump, timing set, and harmonic balancer at the same time, since it'll be much easier to do on a stand or hoist. If you can find a later oil pan (98 & up, I think) it might be good to replace it since the new ones hold an extra quart of oil.