66 Mustangs

[Gonzostyle]

I have located a 66 mustang coupe for a VERY decent price. I am curious if someone could help me out with what to look for (problem areas) when I go inspect it. Also, the car is currently a 6cyl/auto how difficult is it to swap out to a V8? Thanks.

-Jeremie

[Steve1968LS2]

I do know that 65's and 66's have less room between the shock towers than say a 67 or 68 where 351's were put in at the factory.

I have also heard the the shock towers on 67s and 8's need reinforcing on the I6 models if you are gonna shove a V8 in there.. no biggie and I am not sure it is the same for 65/66 (but I am guessing it is)

Trouble spots include.. the lower front corners of both doors. The factory drain holes plug easily there and almost always rust. Check the shock towers also.

I am NOT a 'stang expert so hopefully one will chime in (Ive just been hunting a 67/68 project car and Ive owned a couple 65's)

Good Luck!

[stanglou]

check the cowel which is on the underside of the dash near the driver/passanger door, and the grille at the back of the hood. also chech the lower door sections and behind the rear window at the bottom

[kmcanally]

351's will fit the 65/66...and headers are available....big block? forget it.

All of the above mentioned rust areas plus:

1. If the cowl is rusted and leaking then it is likely that the floor boards
are also rusted. Never judge the condition of the floor pans
with a visual inspection from the bottom of the car. Floor pans
always rust from the inside out so you have to pull the carpet back
for a proper inspection.

2. The lower edge of the trunk lid (near the tail light panel) is also a
rust hot spot on these cars. The barrell nuts used to hold the
"MUSTANG" letters in place let water in and there is no place for it
to go.

3. And then also check the lower corner of the qpanel right behind the
wheel. There is a drain here but like Steve mentioned with the
doors they also get clogged with debris over the years.

[DarkBuddha]

Rust will be your biggest enemy to look for... places to check: the whole damn car. Just kidding, sorta... The cars do rust just about every place they can, but here are the major places that cost serious time/money to fix:

1, Cowl - check it by running water with a hose into the cowl... if it leaks through to the floor = bad. Expensive and labor intensive to fix.

2. Floors and torque boxes - always rusted, if not outright swiss cheese. These are structural on the unibody, so they've got to be done right and it's another big expensive job.

3. Front and rear subframe rails. These were never coated internally, so they often rust out.

4. Trunk floors.

5. Wheel wells.

6. bottoms of doors and door pillars.

7. Front and rear windsheild areas.

8. Hood.

9. Shocktowers and fender aprons. Shocktowers often have rust at the base and the fender aprons rust from battery acid or accident damage. Also, be careful to inspect the shocktowers for cracks or holes drilled/cut into them. It was common practice to drill/cut holes in the sides of the shocktowers in order to access the upper arm grease ports. Shocktowers are structural and a big job to replace, so it can get pricey.

Everything else is manageable and cheaper to repair, like quarter panel rust or taillight panel rust, both of which are common.

As for the 6 to V8 swap. It's been done lots of times, but it is most often cheaper to start with a V8 car to begin with. To do the swap "right", you'll need a complete V8 front suspension setup, including arms, strutrods, springs, steering components, etc. '65-'66 6 cyl Mustangs had 4 lug hubs, so you'll want to step up to the 5 lug stuff including spindle and hubs. The rear suspension will also be weak, likely having a 7.5" rear and soft springs and no sway bar, and again it'll have 4 lug axles. Now, once you get all that, you can do the actual engine swap, but I can't remember if there is any wiring harness stuff to deal with.

Hope this helps.

[Steve1968LS2]

351's will fit the 65/66...and headers are available....big block? forget it.


I know they will fit but I was told there is MORE room (engine bay) in a 67/68 than a 65/66..

Is that true?

[zbugger]

Shoot.. You're making me think again. I think there is more room in a 66 than there is in a 65. 67 is a different design, I think, and it definitely has more room. Big block in a 65-66 is a tight fit. Later models got easier. I know more, but my head is not on my shoulders at the moment. Gotta give me time to remember this stuff.

[SatisTraction]

i had a 69 and that bay was tight with a 351w. i could not imagine a 66 with a 351w

[69rs]

I have seen Mustangs that have had coilovers installed. The shock towers were removed, really opening up the engine compartment.

[kmcanally]

I know they will fit but I was told there is MORE room (engine bay) in a 67/68 than a 65/66..

Is that true?

Yes it is true....the 65/66 is narrower between the shock towers than the 67/68.

The first big block available in a Mustang was the 390 in 67.

[wantahertzdonut]

When you swap the V8 in, be sure to replace the spindles with spindles from a v8 car. There are many horror stories of spindles breaking when a V8 was swapped in, and you can imagine the carnage when something like that goes.

Since it sounds like you'll be doing a fair amount of modifications to the car, you'll likely be replacing all the weaker I6 parts with stronger aftermarket ones. Just be sure to remember the spindles.

In regards to removing the shock towers and replacing the suspension with a coil-over setup, remember you will lose a lot of front end rigidity. These cars rely on the export brace to reinforce the front end, and removing the shock towers removes the mounting point for this brace. I don't know if some of the Mustang II setups have resolved this issue in any way, but you will need to keep it in mind should you decide to swap out engines.

If all you're after is bigger cubes, a 351W will do the job just fine and you shouldn't need to do any cutting. Headers are available for this swap. It'll be tight but not impossible.

I'd recommend considering a 331 stroker for a 302, it'll drop right in without any special parts, and strokers are getting more and more reliable. Even 347 strokers are getting to be very good, as companies are finding ways to eliminate the oil burning issues these big stroker kits were having. Then you'll have the HP, with little weight, and for less cost.

[Gonzostyle]

Thanks for all the input!! I went and looked at the car last night, contrary to the add the car was severely rusted. I decided to pass on this one.

Thanks again,

-Jeremie

[DarkBuddha]

Rust will be your biggest enemy to look for... places to check: the whole damn car.
Sometimes I hate being right... sorry to hear the car didn't meet your expectations. You'll pay more for a more solid car, but you'll be thousands of $$$ ahead in the long run.

[kmcanally]

Thanks for all the input!! I went and looked at the car last night, contrary to the add the car was severely rusted. I decided to pass on this one.

Thanks again,

-Jeremie

That sucks....most people selling these cars would not know where or how to locate rust...

also, don't you get tired of looking at cars that are not at all accurately described in the ads? Since when is the definition of restored a cheap paint job and a rebuilt motor? That should be listed as "recent paint and rebuilt motor". My definition of restored is tear it completely apart, refinish or replace all of the parts and then put it all back together.