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1966 Mustang Convertible -- Poor handling caused by Rim, Tire and Suspension Blocks?

1315 Views 25 Replies 11 Participants Last post by  Flade
Hi everyone,

My Dad bought a 1966 Mustang Convertible last year that was orignally a V6 that was converted for a V8. He owned muscle cars back in the 70s and loves the Mustang, but seems to have concerns with the way that it handles. He says that it's really tough to handle at highway speeds, and we're hoping to make things right :)

It currently has some 4-lug American Racing Outlaw II Wheels that I believe came from CJ Pony Parts, as well as some Mickey Thompson tires. I can't seem to find the tire sizes, but the sidewalls say:
  • Front Tires:
    • Mickey Thompson 60 Indy Profile
    • D60-14
  • Rear Tires:
    • Mickey Thompson S/S Indy Profile
    • G60-14
I'm thinking that this wheel/tire fitment must not be appropriate for the car, since the front end suspension had to be blocked up to make space in the fenders, and I believe spacers are installed as well. I suspect that something in the combination of the suspension blocks, wheels/spacers, and tires are causing the handling concerns (and my bet is on the suspesion blocks that seem kind of sketchy). Does anyone have advice on where to start? If we changed the tires could he remove the suspension blocks? He loves the look of these rims, but wants the car to handle reasonably well.

Thanks!

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First and foremost, it needs swapped to v8 spindles and complete v8 suspension and brakes in the front. The rear, while safe, is very very weak and will probably need swapped to an 8"/9" rear, if for nothing else so the wheels match. There's a reason why it's a handful to drive....
 
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Discussion Starter · #3 ·
First and foremost, it needs swapped to v8 spindles and complete v8 suspension and brakes in the front. The rear, while safe, is very very weak and will probably need swapped to an 8"/9" rear, if for nothing else so the wheels match. There's a reason why it's a handful to drive....
Thanks! I didn't consder that the V6 and V8 would have different suspensions. I suppose the V8 suspension would accommodate a heavier engine or something like that? Would that be a big improvement in handling and eliminate the suspension blocks that he has?

When I drove the car, I was more concerned about the braking power than the handling (I believe it's drum brakes all around). My Dad's convinced braking isn't an issue, but I've wanted him to consider a brake upgrade.

Do you know how big of a job (ballpark) it would be to do the suspension/brake upgrade you described?

Thanks!
 

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The brakes are smaller on the I6 cars (just fyi it wasn't a v6, it was an inline 6) and will need to be swapped to v8 brakes. It appears who ever did the swap did the lipstick on a pig type of work by puttng those twist in style spring blocks. The size of the job totally depends on your experience level and the amount of tools you have. I'm betting it still has the single bowl master cylinder...that's gotta go as well.
 
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Discussion Starter · #5 ·
The brakes are smaller on the I6 cars (just fyi it wasn't a v6, it was an inline 6) and will need to be swapped to v8 brakes. It appears who ever did the swap did the lipstick on a pig type of work by puttng those twist in style spring blocks. The size of the job totally depends on your experience level and the amount of tools you have. I'm betting it still has the single bowl master cylinder...that's gotta go as well.
OK thanks again! I like the idea of swapping both the brakes and the suspension at the same time to improve the handling and braking. The twist-in spring blocks scare me, and hopefully with a proper V8 suspension they're no longer needed.

My Dad would pay a trusted mechanic to do the work and doesn't mind paying some money to get things working the way it should. I see that there are suspension and brake conversion kits on CJ Pony Parts so we can start there. He just wants to be able to enjoy the car on the highway :)

Thanks!
 

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OK thanks again! I like the idea of swapping both the brakes and the suspension at the same time to improve the handling and braking. The twist-in spring blocks scare me, and hopefully with a proper V8 suspension they're no longer needed.

My Dad would pay a trusted mechanic to do the work and doesn't mind paying some money to get things working the way it should. I see that there are suspension and brake conversion kits on CJ Pony Parts so we can start there. He just wants to be able to enjoy the car on the highway :)

Thanks!
Just an fyi, CJpony is the walmart of the mustang vendors, without the customer service to at least get your money back. There are so many negative threads about them it's not worth it to me to gamble my money on using them. National Parts Depot is one of the best vendors around and the owner is an actual car guy that loves mustangs, and is on this forum regularly. Youll need to find original v8 spindles as I am not sure they are reproduced.
 
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Discussion Starter · #7 ·
Just an fyi, CJpony is the walmart of the mustang vendors, without the customer service to at least get your money back. There are so many negative threads about them it's not worth it to me to gamble my money on using them. National Parts Depot is one of the best vendors around and the owner is an actual car guy that loves mustangs, and is on this forum regularly. Youll need to find original v8 spindles as I am not sure they are reproduced.
Thanks for the advice. I poked around a bit on the Suspension Parts on National Parts Depot and the amount of choice is overwhelming! Is there a specific kit or something that my Dad should be considering?
 

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Those twist-in coil spring spacers were the cheap way to "repair" sagging springs and they are surely part of your problems.
Another word of warning- those tires must be at least 40 years old as the D60-14 and G60-14 sizes have not been used in the past 40 years or more. I would not drive anywhere (even around the block) on those tires. The cost of repairs to a front fender or rear quarter panel when one of them comes apart will exceed the cost of a set of new tires.
As others have stated- you need to replace the complete suspension and steering system along with the rear axle on that car. The I6 (not V6) parts were not up to the task of handling V8 power. In making the swap to the V8 parts you will have 5 lug bolts on each wheel so your current wheels won't fit. Your dad will need to find some matching wheels (or as close to matching as possible) with 5 lugs.
If you don't have the ability to do the work yourselves post your location so somebody can advise you of a shop to do the work. I can guarantee you that there are shops out there that will tell you they know how to do it but they have never seen the shims used to adjust caster and camber on a '65/'66 Mustang and they will screw it up.
Since you are new to the Vintage Mustang scene please ask questions before doing anything so that we can save you a lot of money and headaches with the experience you will find on this website.
 

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Thanks for the advice. I poked around a bit on the Suspension Parts on National Parts Depot and the amount of choice is overwhelming! Is there a specific kit or something that my Dad should be considering?
You don't need any of those fancy, high dollar suspension kits. You just need stock replacement parts including upper and lower control arms with ball joints, coil springs, steering center link and tie rod ends, pitman arm and idler arm. You will need to acquire a pair of '65/'66 V8 spindles, hubs and brakes and a '65/'66 V8 rear axle and brakes which is also called an 8" rear axle. You may as well replace the rear leaf springs while you are at it.
All of these parts are going to cost some money- at least $1000-$2000. Paying somebody to do all of the work is going to cost another $2000 or thereabouts. And you'll need new wheels and tires for another $1000-$2000. It won't be inexpensive!
 

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Without a doubt those antique tires are massively contributing to the poor handling.

Compound that with the wrong springs and suspension and…

While the car looks ok from the outside what’s underneath is a major undertaking.
 

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1988-1992 Ford Rangers, Bronco IIs and Explorers came with a factory wheel that looks almost exactly like your American Racing wheels. They have the same 5 lug bolt pattern as the Mustang wheel. The Ranger/B II/Explorer wheel is available in 14" and 15" diameters.
 

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1965 2+2 Vintage Burgundy A-code C4
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While National Parts Depot is an excellent supplier for parts, I’ll throw in Opentracker Racing Products as well. John the owner is excellent at talking you through what you need, or more importantly what you don’t need. Just another option, you will not go wrong with either.
 
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While National Parts Depot is an excellent supplier for parts, I’ll throw in Opentracker Racing Products as well. John the owner is excellent at talking you through what you need, or more importantly what you don’t need. Just another option, you will not go wrong with either.
I second Open Tracker
. The parts are great & John is a nice guy to deal with.
 

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Discussion Starter · #15 ·
Thanks everyone, this is a lot of useful info!

Wow, the tires are 40+ years old?! I thought they were just antique-looking tires, but didn't realize the were actual antique tires haha! I guess that explains why I couldn't find the size like "P185/75R14".

From all the advice here and awhtx's helpful ballparking, it sounds like there's a fair amount of suspension work needed to improve the car's handling, but my Dad's OK with spending some money to do that. He really likes the car, but just wants the drive to be comfortable. We're actually located in Guelph, Ontario (Canada). I'm not sure if there are any other Canadians on here, but I'd be interested in shop recommendations.

Thanks!
 
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