Im looking to buy these will and i want either a 18x10 or a 20x10 for the rear will they fit i have a 10 bolt rear end out of a 69 chevelle on my 70 olds now but will be going with a 12 bolt any info would be greatly appreciated

 

You have not provided enough info for anyone to answer the question. What's the bolt pattern, backspacing, and offset? What tire size?

 

If you have 10-inch wide wheels on the car now with the 10 bolt then you're ok. Just measure the overall width on the 12 bolt to confirm it is the same as the 10 bolt. Some rear axles change width. If it is the same, no problem. If I was testing an unknown axle, suspension, or spring I would bolt it up some smaller rollers for a baseline measurement. Take some turns on dips to really test the limit of travel. From there add wheel and tire size. In case you have future plans for the suspension remember that spring height and tension will be a clearance factor. Make sure ride height and spring firmness are final before choosing wheel size. Every fraction of an inch will get you closer to rubbing so establishing the baseline measurement is important.

They sound awesome, hope to see pics when you have them done!