why go 85

If installing a 6m, then 84+ is easier because all of the accessory pulleys, pwr steering, alt, a/c, water pump, match and line up with the 6m crank pulley. If you put a 6m in 82-83, then you have to source those pulleys from an 84+ supra or possibly cressida. But now on to the more important advice: Do Not, and I'll repeat with more emphasis, DO NOT! build a 6m turbo unless you already HAVE a 6m in your car, in which case the principal of sunk cost applies. And apparently you haven't even bought a chassis to start with yet so there is hope that we can save you from wasteing thousands of dollars. For nearly the same money as buying a used 6m and turbocharging it, you can buy a wrecked mk3 turbo parts car and swap the whole motor, ecu and everything. Then you'll have a toyota factory turbo motor thats far more reliable and since you want to make 15psi, there's still some aftermarket support for the 7mgte as opposed to NONE for the 5m/6m series. About the most you can SAFELY get out of a 5m or 6m with turbo and the stock ecu and injectors is 8-10psi. Beyond that, you need programmable ecu and much larger injectors and thats much more expensive than a 7mgte swap which can get you to 12-14psi with only a few upgrades.

Phil D.