69 Camaro mini tub backspacing?

[69Camaro]

Hey guys,

I will be ordering a set of Forgeline GA3's from Matt's Classic Bowtie's by the end of the month. I am building a 69 Camaro with Ridetech level 2 suspension, tru-turn and DSE minitub. I have not ordered a diff yet and I will measure that after I mock up the wheels and measure WMS to WMS.

My question is, what is the most common rear wheel back spacing? I will be running 18x11.5 rear wheels so I can use either 335 or 315's depending on tire availability. I would like to have a common backspacing so that if I want to sell the wheels down the road there is a better chance of them fitting other similarly built vehicles. Does that make sense?

Currently thinking of 18x9.5 front 5.75 BS, 18x11.5 rear ?? BS.
BFGoodrich Rival S, 275/35/18, 335/30/18

Thanks in advance for the help and advice, this website is a large portion of the incentive to build my car.

[dontlifttoshift]

Just an FYI. The 315s will work fine on a 12" wheel, no need to compromise the 335s.

General rule of thumb has been that you need 5.5" of backspace, minimum, to ensure caliper clearance to the frame rails. You will find that most minitub 1st gens are running 5.5 to 6.5" backspace.

[tubbed69]

Like Donny said why not run 12" wheels?most common bs is 5.5" that's what DSE uses and sells on their rear diff.

[69Camaro]

Thanks guys, I have been researching backspace for a couple weeks now and there are several opinions. Some from guys with finished cars, some from guys with obviously mismatched components that have problems, others have painted cars and can't tolerate any amount of rubbing and some that are ok with major fender surgery. I'm trying to take it all in and come up with something that will work for my car.
I did find a reply from Bret @ Ridetech that says a 18x9.5 with 5.5 BS will work with no issues on the front. I'm ok with fender mods and minor rubbing at a low ride height, as long as it doesn't crease a fender once it's painted I'm good.

Unless anyone can see issues I will take Bret's advice and the advice of the guys who were nice enough to post up above and I will order 18x9.5 5.5 BS AND 18x12 5.5 BS for the rear. 275/35 & 335/30's

[69Camaro]

Now, secondary question....

GA3 vs. GA3R for a car that will be 60% street car, 25% auto cross and some drag racing does it matter which wheel I choose?
I figure either will work structurally, any issues with the GA3R on the street?
Anyone have issues with tech inspection and snap in centre caps on the GA3?

I'm leaning towards the GA3 as they are slightly cheaper, but with Matt's pricing it really isn't much difference between the 2 wheels.

Jayson

[Schwartz Perf]

Unless you like the no-cap look, the GA3 will be just fine for what you're doing. I haven't heard of snap in caps being an issue at any events.

-Dale