Larger Wheels And Frame Questions

chevrolet1616 · January 24, 2009

I got 3 main topic questions. Not sure if this is the right forum to use but I'll give it a shot. I got an 04 Silverado Ext cab, short bed w/ the 5.3 4x4.

1) Right now I'm in the mood for new wheels and tires. I'm tired of 16 and 17 inch stockers I've seen. I want to go to 18's but with off road tires. I dont have a lift on it, nor do I want to level the truck out. So what's the largest tire size I can go to right now?

As for the future plans:

2 and 3) I've been planning to turn this truck into a chase truck for some western desert races in about 4 years. I am not happy with the torsion bars on the truck and want to go to coil-overs. JD Fabrication makes a cool kit but 5 grand is very very steep not including the body work. I've talked to some specialty shops and their costs are well above 10 grand. First of all, if I go to coil-overs the front track must increase, so new upper and lower A-arms are a must. Unibal ends using the stock knuckle will work like in the JD Fab example. I only want 8 to 10 inches of travel, dont really need 15 and a hydraulic bump-stop or an additional shock. Fox 4 inch coil-overs are probably the best choice. I can do the design for the A-arms and mounting points and get new CV shafts.

This leads to my main problem.. can the front end handle the different load? The 2wd version of the Silverado had coil cups where the shock cups are in the 4wd version and I have seen the 2wd's do fine with jumps and such out in the desert with no problem. So would it be possible to design a "coil cup" that can handle a coil-over?

I should also mention moving the axle is a definite NO because I plan for this to be a daily driver as well.

If this isn't possible another solution is to mount the coil-over sideways... bear with me. If you have seen race cars that have inbound coil-overs, I have also seen a version of them out in desert racing. Works really well although they have limited travel (around 8 to 10 inches). Granted this type of setup wont work as an inbound but rather parallel to the frame rails. I should have some drawings put up later if people respond.

Thanks to any responders (especially for the 1st one).