A little update. After having moved the engine back 3/4" I mocked up the Frontrunner setup today to check clearances. At first I was mega PO'd and couldn't figure out what had happened. The A/C compressor still hit the radiator fan motors even though previous measurements indicated it *should* fit. Anyway, I pulled a block-face to end of A/C compressor measurement to check against the V/A quoted dimension. It was off and then I noticed the pulleys weren't lined up. Turns out the V/A Frontrunner diagram in the instructions clearly has the spacer in FRONT when it actually goes in the rear. The text of the instructions states the rear too. I moved the spacer and the compressor clears. Still extremely tight though. The spacer fills the gap you see there at the rear of the compressor. There is a spacer on both sides. I just have one side in because it was too tight with the tape on this side

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You can see from the pics that I don't have the compressor front cover or tensioner cover installed. Primarily because I didn't feel like taking the radiator back out again to put it on. The tensioner is the closest point at ~1/8" of clearance. The fan motor to compressor clearance is closer to 1/4".
I'd like another 1/4" but I've got to figure out where to get that from. One of the header tubes is close enough to the steering box that I think another 1/4" setback might cause it to contact. We'll see when I get the mounts build.
So I did run into another unexpected clearance issue. The PS pump reservoir tank is too close to the UCA. This is a Jones Racing aluminum pump with an extra capacity fab'd aluminum tank. Really cool piece. Too bad it won't clear

. I'm gonna see about getting a tank made without the bung on the side. I think that will work. Otherwise maybe a less blinged out OE style PS pump is in order. This pump measures 5 1/2" from pump shaft centerline to the outside edge of the tank. I think the OE style plastic tanks are a little narrower.
Here are some shots of the firewall after the setback. Seems a little tight. That Unilite distributor is pretty small so I'm almost sure the firewall will need to be modified for clearance.
Updated shot of tie-rod to header clearance after pushing engine back. I think a Ridetech TruTurn might clear now.