the only real way to find out if its a 91.5-93 Cummins is to get the numbers off the Engine ID tag. Unless u did the swap yourself, and got the IC and motor out of the same truck.
NO the first gens did not have Wastegates. 94 was the first year for factory wastegated turbo's. I dont care what ANYONE tells u. Thats just the way it is/was.
The engine will spin 3K freely, but not underload when stock. U need a 3200 Gov spring to do that. And with a 3200 Gov spring it'll free rev to almost 4K. And I dunno why the IP would have a Mopar tag on it unless maybe it was a recalled pump truck, and has the replacement pump on it.
It is possible someone has been in the pump before u got the truck. And there are plenty of things u can do to get lots of power out of it too.
First things first gauges, yes I know were beating a dead horse, but its kind of liek a disclaimer. lol
Second clicky here ---->
http://dodgeram.org/support_pgs/diesel_ix.htm
Thats your bible, save it. Also keep in mind the "more power" articles are very conservative, substitute 1/4 turns for full turns, except here ---->
http://www.dieseltruckresource.com/dev/showthread.php?t=154086
Also, before u touch that fuel screw, clicky here---->
http://www.dieseltruckresource.com/dev/showthread.php?t=158962 (EVERY first gen cummins owner must know this)
And when your ready for a better turbo, ask away. Turbo decission is based solely on intended use, and modifications. Dont run out and buy a turbo or itmes for the turbo like an exhaust housing with out fully understanding everything about it. Trust me it'll save u money (lots of it)
And some schoolin~
89-91.5 have a smaller turbo, 50 mm compressor housing and an 18.5 CM exhaust housing. commonly reffered to as the "baby" H1C.
91.5-92 have a larger turbo, 55MM compressor, and a 21CM exhaust housing. The large exhaust housing sucks for spool up.
93 has a 55 mm compressor and a 18.5 cm exhaust housing. all years are an H1C holset turbo.
94+ use a 57MM compressor, and a 12cm wastegated exhaust housing. 94-95 designation is WH1C, 96+ designation is HX-35 same turbo with some minor changes.
Thats a lot to type! Feel free to ask questions if u dont understand something fully, thats why were here!