I am going to assume that you are using all stock parts and we are talking about the long block only. The only difference between turbo and non-turbo long blocks from '81-'83 is the cylinder head casting, and the pistons. Everything else is identical. Therefore, the rebuild price should be the same. The cylinder head on the turbo is the P90 and the n/a is the P79. The combustion chambers of these heads are the same; the P90 has square exhaust ports and the P79 has round ports w/steel liners. The cam is also ground differently for the turbo motor. The pistons in the turbo motor are dished whereas the n/a pistons are flattops. All of the mechanical parts are otherwise identical. Good luck!!!
First and foremost...
the rings for the turbo motor are chromemoly coated and thus are about $30-$40 more expensive than the n/a counterparts.
If your turbor engine will ever see some hi-power you will like to swap in some ARP head and main studs and dor bolts