RacingJunk member curtisreed gave some great tips on buying a drag car on our forum that we wanted to share.
I think a book could be written on this subject. First thing is are you looking at a car fast enough to certify? If so make sure the cage will pass cert. Dragster or door car? If it does have a cage, but not fast enough to cert look at all the welds to make sure they are done well. I always look at the wiring, it tells me how well the car was set up originally. Birds nests are no fun to dig through if you have a problem. Look the suspension over, if it is a four link or ladder bar car make sure the rod ends are in good shape.
If it is a running car, if you could see it make a pass that would be the best. If not you are at more risk with the engine. At a minimum pull the valve covers and look over the springs and rockers. Listen closely when the car is running for odd noises. Go over the whole thing with a fine tooth comb looking for loose items or mounting points. Make sure the fuel system is in good shape.
Get in the car and make sure you fit comfortably. It could have been built for someone 5′ 8″ and you are 6′ 3″. Do you knees hit the steering wheel? I looked at buying a car once and that very thing happened.
Check the depth hole on the slicks and look for weather cracks in front and back tires. Are you going to have to replace them before you can run it? Ask to see the log book for the car. I have a log and time slips from every run since I bought my car ten years ago. I also keep records of clearances and other items from building my engine, trans, etc…
The more info someone can provide you the better. It will make your decision much easier when deciding on buying. One last thing is that I would prefer buying a roller if you can, and building or buying a new engine, but that is just my preference. I don’t want to be worried about someone’s engine building skills when I am going 150MPH. I have probably forgotten some things I’m sure but there is a start.
PS… I almost forgot to add. If it is a dragster look over all the welds really good, top to bottom. Pull the body panels and lay under the car if you have to. Dragsters will break the weld joints riding in a trailer so you have to watch them.