Optimal backspacing for '68 C10

[bamafrost]

Can anybody tell me what the optimal backspacing would be on my 1968 C10 SWB? Unsure whether to keep my 6 lug and have custom rallyes made or convert to 5 on 5. Either way, assuming I'll keep drums on the rear and go with 12" discs up front what is the ideal backspacing? Looking at over-sized rims...unsure if 16, 17.

Also, what's the general consensus on wheel adapters...safe, crazy, dumb?
I know they are not the BEST way to "get there".

Thanks for any help. Tom

[Jim 383]

I've got a 68 lwb with 15x8 blazer wheels.they have 4 inches of back space.They would fit better with less backspace in back like 3 3/4" and more in the front like 4 1/4 or 4 1/2. I've got 285/70s on back and 255/70s in the front.I never had clearance problems until it was lowered with 2 1/2 drop spindles,maybe disc brakes widened the track a little.These trucks come with a wider track in front.

[bamafrost]

Jim...Thanks for the reply. I have some killer Torque Thrust ST's (18" fronts/20" rears...with 5 1/2" backspacing) ...but the only way they'll work is with 1"-1.5" wheel adapters and that concerns me. Have a buddy that has them on his race car and says I don't need to have any concerns.

Any thoughts on their safety? Las thing I want is to get this thing just the way I want it and have it get even lower while doing 70 mph. haha

Thanks again. Tom

[screamin_c10]

Just keep in mind that 5 lug axles (71-72) are wider than their six lug brethren....So if you plan on going that route on your conversion it is going to change things as far as back spacing is concerned.....

[Jim 383]

Modern aluminum billet spacers 1.5 " thick are probably stronger than your wheel centers. The old cast potmetal ones are the ones that established the bad reputation.A spacer that bolts to the hub and the wheels bolt to the spacer is the best way. A spacer that requires long studs is the worst.Some racing sanctioning bodies don't like spacers,but for just driving around with light loads I wouldn't worry I'm not any kind of expert though.It does give you a chance to fine tune the back spacing too. I have some on my Chevelle, I jacked it up put the wheels where i wanted them and measured the space between the back of the wheel and the hub.

[ap2002]

I have some 16x10 6lug on my 68 they tuck in very nicely, but i cant remember the backspace, i want to say its 5.5? ill double check

[ap2002]

bolt pattern: 6lug, 6x5.5
offset: -24mm,
backspace: 4 1/2"

[bamafrost]

Thanks for the input, I appreciate it. Tom