First off, I'm on a budget of around 4K. I have a 350 bored .60 over pushing about 350HP and a 4 speed behind it. Right now I have a 10 bolt non-posi (mono-leaf) in my Camaro and I'm looking to fit a 295 plus wide tire underneath. I will not be drag or road racing, I just want the fat tire look on a 19 or 20 inch rim. I know I'll need a mini tub, but I'm not sure which way to go with coil overs or lowered leafs? Should I keep the 10 bolt or go to a 12 bolt/ Ford 9"? What kind of rim backspacing is ideal for this kind of set up? I don't have the required knowledge or tools to do this myself so I'll be going to a shop to get this done. Just looking for some insight on what people have done and/or recommend. I'm located in San Diego, CA. so if you know of a shop that can do this on my budget, hook me up! Thanks for anyones help ahead of time!

-Nick

I've got a 68 as well. If you get someone else to mini tub & rear suspension your over your budget already. It's major surgery with hours & hours of labour charges. I would guess most would go with Detroit Speed & Engineering parts (Quadralink set up & minitubs).
I chose not to tub and fit 275/40 ZR17 Nitto tires with Billet Specialties rims. Ordered them through Newstalgia over the internet. They arrived via UPS mounted & balanced. If you call them they know the backspacing that won't rub.
I had the monoleaf as well and made the mistake of going with a lowered multi-leaf. It rides like crap. Way to stiff. I added a sway bar and caltrac traction bars which were fine but the spring rate on the lowered leafs was a bad option. I'm looking at a do-over option with coil overs for adjustable ride height with 3 or 4 link set-up. I'm looking at the Detroit Speed quadra link but no mini tub (it still requires sheet metal surgery). The other option I'm looking at is a triangulated 3 link with coil overs that looks like a straight bolt-in (speed Tech Performance). If I choose the Detroit speed option that means slicing up the sheet metal in the trunk for a cross member and two rectangular holes under the rear seat and welding in the brackets for the links.
I'm leaning heavily to the Speed Tech set up. I too have a 10 bolt in the rear. It's a 8 & 1/2 inch out of an old Nova and have heard it's stronger than the smaller sized 10 bolt. Changed out the gears, bearings, etc. I haven't broke this set-up with 430 Hp pumping out at the rear wheels (so far). That being said, it's not the main stream rear end that most street muscle cars would go with. Most of these companies offer a rear end that they have added brackets to adapt their products. I'd go that way in do-over world.
Up front I went with the Detroit Speed control arms and coil-overs. Works well.
I have the Tremec TKO 5 speed overdrive transmission and 3.73 gears in the rear end. Highway speeds staying up with traffic revs are around 24-25k. I'd say top speeds are limited. I've had it up to about 95 mph and it revs the snot out of the engine. Good low end torque but a tradeoff on the bat out of hell speed passes on the highway.
Good luck