quote Originally posted by katatak: Still on the lookout for an LS6 Intake - they are just really scarce in my neck of the woods. Car Craft did a nice cam comparison on a LM7 5.3 truck motor. Some interesting results. I need to read some more - there's the single bolt, 3 bolt, rear cam sensor, front cam sensor........... My LS4 has a front cam sensor and I believe in 06 had a 3 bolt. I'd like to use a GM stock Cam - mainly due to cost and not looking to do any thing radical - most the stock LS cams can be had for 150.00 or less. When looking at the Crane Cams, Comp Cam, Lunati, etc. they are going 300 plus, require other springs, etc etc. I have a brand new set of LS7 Lifters and lifter trays and the LS6 springs so a decent stock LS2, LS3, LS7, LS9 cam would fit. I'm thinking with the Auto trans I want to try and keep the Torque up in the lower end? Everything up from the LM7 Cam looses low end (2500 rpm) torque. I think the LS2 and LS3 loose 18 to 21 tq at 2500 vs the LM7 cam (keeping in mind these numbers are using the Holley EFI but I am thinking the "spread" would be similar with the LS1 or LS6 intake? All this makes my head hurt.......

Do you really need an LS1 or LS6 intake and the 78 MM throttle body? The LS2 can be had cheaper, and has proven to outflow the LS6 intake at key points. All the LS1/LS6/LS2 stock intakes will flow less than the #243 heads will flow stock, anyway, so they will all be a limiting factor. The throttle body is of course going to be the expensive part of going to a 90MM throttle intake. You could use an adapter and stick with the LS1/LS4 throttle though.

As for the cam, if you're using an 06 engine, and 06 computer, you're on the 24x crank reluctor, which means you have to use a 1x cam gear. All the 1x cams are 3 bolt. If you're not porting the heads and such, then the best option for you will probably be an LS1 (or LQ9), LS6, or LS2 camshaft. An LS7 camshaft could be used, but a 5.3 with stock heads is not moving enough air to make use of it. It will allow flowing more air than your engine can handle.

So after a long time of tinkering, I decided to sell off the LS4 roadster / IMSA project. Just too much work and too little time. Fortunately, the pieces and parts are going to Fiero Folks that will take them to the next phase. I had the LS4 mounted in the Roadster Chassis and dropped it out this afternoon. Once I had it out and on the stand, it hit me. This could very well be the last time I drop a motor out of a Fiero! The next Fiero I own, will come done the way I want. Just want to get in it and drive it. Until the next one comes along - I'll be lurking in the background. Here's a few parting shots of this project before Cliff sends it to the Archives.