Hello everyone....I have a few questions about swapping a 6.2 in place of a 350 tbi on a 1990 Suburban. From what I've read so far on this site and fullsizechevy.com(from where I got directed to here!, the conversion doesn't seem to difficult. The motor mounts will need changed, the tranny(700R4) will bolt up, but will need recalibrated shift points for the diesel. I can use the stock fuel pump as a pickup pump for the injection pump (after I remove all of the gasoline from the tank). I may need to beef up the cooling system, as I currently have a 3 row radiator; might need a 4 row. I should be ok about the front suspension capacity(snowplow springs). Also know that I should go to a dual battery starting system. Questions...What wiring is involved to the 6.2? What do I do about the current wiring for the TBI? Should I find an older dash panel with mechanical speedometer? Do I have the basic ideas correct on this and am I forgetting anything? Thanks in advance for the help!

No need to change the motor mounts. I would add more, but I have to shut the computer down. In the middle of a bad thunderstorm...

I guess I forgot to say in my first post: Welcome to the forum!

Keep in mind that if you use the lift pump in the tank you will need a pressure regulator. I would recommend using the stock 6.2 mechanical lift pump.

As far as wiring goes:

You can just hook the power lead for the HEI to the injection pump. You will need to wire up a glow plug system which isn't hard, you basically need a source for 12V and the controller does the rest. You should be able to hook you oil pressure and coolant temp gauges up without modification.

I don't think you need to find a mechanical speedo. The one you've got should work fine.

Well, I'm just thinking that the speedometer runs thru the computer, and won't the computer kind of freak out without the normal engine?

Hmmm.. That's true. I forgot about that. I've been working on these basic diesels for to long... It's time to work on a gasser so I can remember this stuff...

To change to mechanical speedo you will not only need a gauge and a cable, you will need to convert the speedo output on the tranny to mechanical. I used to know how to do that, but I don't remember anymore. There is a website out here somewhere with a page about converting... If I could only remember what it is...

the speedo should work just fine. I done the same swap to my 80- model dually about a year ago. I had put a nv4500 in it a year before and had to go to the quartz style dash to get speedo that worked with the tranny cheaply. Fairly easy swap just bolted in 6.5 turbo then moded the a/c box with s10 parts. Wires pluged up for the temp and oil pressure, used hei wire to power pump. Build manual setup for glow plugs.