Trouble spots to look for on old Mustangs?

bobs68 · 12-12-2009, 11:33 AM

I've found a 1966 Mustang for sale. 6 cyl, 3 spd, no air. It appears to be in good shape from the pics. Same guy has owned it since 1970. Thinking of dropping a 289, if I can find one, or a 302 in it. I assume the current transmission probably won't stand up to the HP and torque of a V8 very long, and I might have to relocate motor mounts to accomodate an 8 cyl?? I want to have my mechanic give it the once over if it passes my initial inspection. What are some areas to pay particular attention to for rust or other problems? I can get just about any body part replaced, but of course I'd rather not.

65coupe · 12-12-2009, 11:34 AM

under the battery, in the end of the rear window area (where all the water sits) inside the doors, I had some in the trunk also.

the 3 speed is a toploader is it's stock, which will hold up to a v8.

John66 · 12-28-2009, 07:13 PM

look at the floor pans under the carpet...old mustangs were bad for their cowls to leak

check the rocker panels for any rust...also the inner trunk corners...if this is a northern car, there will be substantial rust here if not taken care of...run a magnet along the outside of the car

66snake · 12-28-2009, 07:19 PM

You need to upgrade the front suspension to V8 parts.
Might as well do the Shelby drop & improve handling while you are at it.

dan46 · 12-28-2009, 07:25 PM

I'd pull the carpet up in all 4 footwells before making a decision to buy it. That should be a pretty good indicator on the extent of the rust, if any exists. Additionally, the cowls are famous for rusting and leaking water. I'd run a hose over the cowl area to check. To me, I'd have no interest in building an old nail like an inline six. I think your on the right track with a 289/302 transplant. Maybe even a stroker. I'd convert to a 4 speed as well. The early six banger Mustangs came with 4 bolt wheels, so you will have to consider upgrading there. The good news is the upper & lower control arms are the same as a V8. I'd consider performing the Granada disc brake conversion. It's cheap and it's a direct bolt on and you'd kill two birds with one stone. You will still need to buy springs. I've done this swap numerous times and the car sits really low with the 6 springs. And the ride quality sucks. You can find 8" V8 diffs for those cars all day long. Buy the whole assembly drum to drum. You will need a unit that is a 66 or earlier because in 67 Ford increased the track. Or you can step up and go for the 9". I've done numerous 6 to 8 swaps along with the diff and Granada DB swap. There's a ton of info on the net about all of these swaps. Hope this helps.

cameron55 · 12-28-2009, 07:29 PM

Quote:

Originally Posted by dan46

I'd pull the carpet up in all 4 footwells before making a decision to buy it. That should be a pretty good indicator on the extent of the rust, if any exists. Additionally, the cowls are famous for rusting and leaking water. I'd run a hose over the cowl area to check. To me, I'd have no interest in building an old nail like an inline six. I think your on the right track with a 289/302 transplant. Maybe even a stroker. I'd convert to a 4 speed as well. The early six banger Mustangs came with 4 bolt wheels, so you will have to consider upgrading there. The good news is the upper & lower control arms are the same as a V8. I'd consider performing the Granada disc brake conversion. It's cheap and it's a direct bolt on and you'd kill two birds with one stone. You will still need to buy springs. I've done this swap numerous times and the car sits really low with the 6 springs. And the ride quality sucks. You can find 8" V8 diffs for those cars all day long. Buy the whole assembly drum to drum. You will need a unit that is a 66 or earlier because in 67 Ford increased the track. Or you can step up and go for the 9". I've done numerous 6 to 8 swaps along with the diff and Granada DB swap. There's a ton of info on the net about all of these swaps. Hope this helps.

This is good info.

Another common rust spot, other than those mentioned, is around the tail lights. Also check those subframe panels, and torque boxes out real well, and if they have put any kind of coating on them, scrape it off so you can see the metal.

281boss · 12-29-2009, 10:03 AM

I vouch for the pulling of carpet. Also check around the rear window and rear quarters. Just my problem areas.

65fastback · 01-12-2010, 10:18 AM

also check if any metal has been replaced. If you look at the floor pans and see a patch or a section replaced that isnt good. That might mean there is more rust elsewhere or at least there once was