Cummins into 1990 1/2 ton suburban
 

Ok, so I swapped the 6.2L Chevy diesel in my 1990 suburban with a 12 valve Cummins, 5 speed getrag, front and rear axles all from a 1991 w250 donor truck. Swap went great! Everything was going very well until I had to renew the tags and get emissions. The emissions testing station said they couldn't test it because of the motor swap. So I went to the state inspection facility to get the proper inspection for testing. After an hour of waiting they came out and told me since the Cummins came out of an 8500 gvw pickup and my suburban is 7300gvw it's not legal anymore. They told me Cummins were never put into a truck under 7300 gvw. Has anyone run into this, maybe have some suggestions? I'm trying to find a way to register it out of Denver metro area, but running into proof of residence... Fearing it's in the "system" now I might be sol. Spent a lot of time on this project only to have bureaucratic BS tell me I can't get registered.

Any thoughts or ideas would be greatly appreciated.

Thanks