You have several options for both sensors really..The coolant sensor can go several places, its really up to you. Some guys have used a T and put it right in the stock sensor location(the upper sensor on T Stat housing). This way, all you need to do is find a 3/8" brass T, and your stock and GM sensors will be right at the stock hole in the housing. Or you can do like I did, and drill/tap the housing for the GM sensor. I opted to tap the housing, just because I really wanted a constant flow of coolant over my sensor. It prob doesnt matter at all, but that's the way I wanted it.

As for the IAT sensor, you can put it anywhere in the intake mani, or even before the throttle body in your piping. I did what etx did and drilled/tapped the EGR hole in the intake. I wasnt using this hole as it was blocked off, but also, you should really countersink the hole, as the tip of the sensor doesnt really stick into the air stream if you just tap the hole only. Really, the easiest solution if you want to keep the stock IAT, is to weld a bung onto your piping, right before the throttle body.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
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-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)