Installed Northstar Throttle Body and LQ4 MAF

On 1/14/2006 I installed a Cadillac 4.6L V8 Northstar Throttle body and LQ4 MAF sensor from a 6.0L V8 motor that is in GM trucks.  The inlet of the Gen5 supercharger is 75mm and by putting my stock GTP throttle body on the Gen5, I was really restricting the intake of my car.  So fortunately, somebody on the Regal GS forums started to make a Gen5 to Northstar adapter that would allow the throttle body to be installed.  There was another option besides the Northstar, the LS1 throttle body from the Camaro/Firebird but the throttle cable linkage was on the wrong side and I would also have lost the function of cruise control.  Both the LS1 and Northstar have 75mm inlets, but the Northstar was a better option.

Anyway, it took a month or so until the adapters were made, so I began to piece together the other parts needed in the meantime.  I got a LQ4 MAF off of eBay and the TPS and MAF wire adapters from  In early January, the adapters got done being made and I ordered the adapter and the throttle body.  Here are pictures of the kit when I received it and the L32 EVAP block-off plate that I made prior to installing the throttle body.

So I installed the throttle body in about an hour or so.  I planned on re-doing my intake tubing with a heatshield and a 7" cone filter into the fenderwell, but the weather got really bad out so I just hooked up the old tubing and filter.  I'll redo the tubing later.  Anyway, here are pictures of the install.

Everything went ok once I got the throttle cable bracket adjusted correctly.  Throttle response is much better, but I can't tell a performance increase yet because I need to tune it in.  Right now, it's running quite rich causing a loss of power in the upper RPM range but I'll get it tuned in.  Next stop, headers!

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