Your idea is intriguing to me, kv1. What you are planning is nearly exactly what I just scraped... a 6.2 conversion on my 1988 K5 Blazer. I personally did not have the time to perform the swap due to college. I have done my research on what all it takes for the 350-to-6.2 swap and while it is not terrible, you need to be wise. A lot wiser than I was! Anyways...
- The 6.2 you choose needs to be checked over
thoroughly for block cracks, crank cracks and main web cracking. These motors just have a knack for developing these issues. If you can have reputable background on the motor and/or listen to it run, by all means the better!
- Make sure that the accessories come with the engine. Does not seem like a big deal till you are scouring junkyards in the snow looking for brackets, pulleys, ect... I know all too well
- The fuel tank will need to be pulled, drained and cleaned. New fuel lines will need to be run also. I suggest bypassing the mechanical pump in favor a quality (NOT Mr. Gasket) diesel fuel pump. I think 5-8 psi. is what you are after, it does not take much to feed the injection pump. While you are at it, this would be a good time to have your injection pump and injectors checked for problems
the stock fuel filtration system is okay, but you can make an inline filtration system on the frame that will work better.
- Cooling system. The stock radiator
WILL NOT be sufficient to cool the 6.2. A diesel puts out more heat than a gas motor. A radiator meant for the 6.2 or 454 that will fit your vehicle will be what the doc prescribed.
- Glow plug relay can be bypassed to a switch in the cab to make better use of the glow plugs. If you are unsure of what this is exactly, Google will be your friend, as there are even diagrams out there detailing this!
- Basic tune up parts such as glow plugs, timing chain, injector lines, vacuum lines, etc.
- Hydroboost brakes is a must!
- the stock gasser exhaust is sufficient for the 6.2 (barely). I would delete the cat, as roflwaffle mentioned earlier, and change that demonic y-pipe! It is a flow killer.
I know this seems like a lot of stuff needed, bud. I do not want to kill your dreams, but I do want you to have a idea of what all your plans have in store for you.
& btw, I'm pretty sure I have left somethings out
and if at all possible, buy a complete truck and swap the drivetrains. When you're done, sell the truck and keep your awesome van!
Maybe oilpan4 will chime in and give some wisdom. He is smart when it comes to the 6.2's.
If you have any questions, don't hesitate to ask!
