Actually that torque curve chart is close to what I'm looking for. I'm wanting to run the engine at near peak torque output and it looks as if I can run the engine at about 3K giving a bit of width to the bellcurve before the developed torque falls off significantly. This should compensate for shock loading of the engine from the air clutch calling for building air, to not compressing air. I plan to install an AMBAC electronic governor and actuator to control engine speed. Hoping I can share the crankshaft position sensor for dual purpose but can always mount another "hall effect" sensor to count ring gear teeth.

I have a buddy whom is a mandrel pipe bender and we are going to fabricate an upswept header to exhaust through the roof as the original engine does using equal length tubing. Haven't decided if this will be stainless but most likely to keep the lifespan into the future. Personally, I like the sound of an inline six at work and this will be music to my ears once it's going.

Thanks for your help on the project.

This sounds like a great little undertaking. Please, we're begging here, post up some pictures. Heck, we can probably find a volunteer to slip over to take and post the pics for you!
Hope it goes well for you.

Had a buddy make a flywheel housing adapter, (Jeep 4.0 to SAE #2) which was plasma cut from 1-1/2" aluminum 6061 plate to bolt the engine up to the compressor. I will need to acquire a manual transmission flywheel as to use the automatic's flexplate and torque converter presented a clearance problem driving the compressor. A short driveline using small Spicer 1310 series universal joints will work fine, and should fit the the torque requirement. I have larger, but had these needing expended.

Pretty slick to start from a cardboard tracing of both mating surfaces to the finished product of a single hunk of aluminum.

I did speak with Worthington whom is the manufacturer of the compressor and they state it can be run at 3250rpm safely if I increase the oil supply and add an additional cooler to the set. No problem as this is a bit less expensive to incorporate than messing with gear reduction for a one off project.

More later as it comes together.

Thanks,