I have a center bolt (1987+ roller motor) 305 SBC motor in an S10. Mileage is unknown as I bought it in the vehicle and the gauge cluster is aftermarket. It's still in the vehicle so you can hear it run. I can't see the casting numbers on the block but can see it stamped 5.0; it looks like it's out of a camaro/firebird based on the serpentine belt setup. If you are serious about purchasing it I will pull a valve cover to see what the heads are (to determine what it came out of). It has an aftermarket edelbrock intake and I believe a Carter carb. It runs strong, lights up the tires with wimpy gears on the S10 but I have a 350 to put in it.
It sounds like it has a small cam in it although I do not know for sure. When I pull the motor out I can pull the timing cover and determine if it's an aftermarket cam (don't factor it being an aftermarket cam into the price though cause I will require a deposit before I pull the motor out - think of it more as a free bonus if it is cammed).

Motor will be sold fully dressed (from oil pan to carb) minus the belt accessories and headers. It runs good and doesn't appear to burn oil (the oil isn't showing up on the plugs or valves).

Looking to get $300. Contact me via email at zraffz@gmail.com or message me on the forum.