Stick With 4-Lug or Upgrade to 5?

[sopwith21]

Howdy friends. My 1980 Mustang is soon to undergo a complete restoration with some pretty heavy modifications. It will be done by a restoration shop, not me. Should I stick with the 4-lug wheels or upgrade to 5-lugs?

Here are the factors to consider:
- Currently has 15x7 Anson Slots. They look very nice and I like them, but I think a 16" or 17" wheel would look better and fill out the fenders.
- Thinking about going with 1990s style Pony chrome wheels. They are available in 17x8 4 lug.
- Some pals of mine regularly race 4-lug Foxes. They seem to hold up under full race conditions with no breakage or trouble.
- My 1980 was originally a 4 cyl 4-speed. It has now been converted to 347 Stroker (425 hp) with T-5 tranny and 3.73 gear. Additional stress sure to follow.
- Suspension upgrades will be made along with lowering springs, sub frame connectors, etc.
- The car will be designed and used for high performance, spirited street driving from with a designated fun zone from 30-60 mph.

I'm trying to think of a convincing reason to upgrade to 5-lug wheels, but it seems that there are also plenty of very nice options if I simplify and just stay 4 lug.

Any thoughts on the matter are appreciated.

[erratic50]

Go to 8.8 or 9" out back either way.

T5Z or Tremec TKO or T56 strongly recommended

5 lug reasons:
wider wheel selection
bigger brakes - 12" 99-04GT or 13" 04 cobra
better calipers - dual piston readily available and cheap
readily available performance calipers, pads
hub style bearings - no mess or fuss
Steering Ackerman vastly improves vs stock
brake line adapter or double flare needed
rear 5 lug disc via SN95 with northern machine brackets
Ceramic or carbon fiber pads

4 lug reasons:
historic or nostalgic wheels
brake upgrade to 11" available via 87-93 GT rotor if spindle swapped
ackerman is improveable if using 84-86 SVO / 82-83 continental spindles
bigger brakes available via spindle mods
still 4 lug, still tall hats, still packable bearibgs
rear disc via turbo coupe and northern machine
Carbon fiber pads

Gut stock, use LMR proportioning plug
summit adjustable proportioning valve
mark VII 1" bore master cyl with standard fox booster
brake line adapter needed, off shelf part at mcparts

for correct operations, get NOS control arms-- replacement bushings use an inner bushing move on rubber design vs stock rubber flex design .


For 5 lug swap in low friction 94 balljoints

Wider K member (91-93) or longer control arm (94-95) suggested. Or camber bolts may be needed even with caster/camber plates

caster/camber and strut brace strongly recommended. Maximum motorsports.

lower K-brace recommended too

Good luck

[erratic50]

I run stock GT springs with X2 balljoint and caster/camber plates. Front is dropped 1.5"

rear i run 4 cyl LX springs, no sway bar. Shortened springs

my car is 5 lug

stock replacement 87-93 struts

stock replacement shocks

no rear sway bar.

stock GT front.

rims are 17x8 SN95 tribal.

tires are 245/45/17. If I had to do it over I'd go 255/40/17

rides great, corners very well


Cheers!

[qikgts]

I think many of us battle with the same choice at one point or another, Steve. There are really a ton of ways to upgrade with stock FoMoCo parts and if you want more or something specific the vendors have great offerings too.

I initially thought about going to 5 lug with all Ford parts on my '85 with '94-'95 Mustang spindles/SN95 Cobra brakes up front paired with a complete SN95 8.8" disc brake rear and using a 1" bore dual port MC from a '73 Ranchero (I wanted the stockish look of a cast MC) and a aftermarket proportioning valve. The SN spindles with their sealed bearing/hub assembly makes brake maintenance super easy and you do wind up with a bigger choice of both stock and aftermarket calipers to choose from so it has clear advantages over earlier Fox spindle based setup's.

Things changed though and I wound up staying four lug using aftermarket rear brackets and other stock Ford components both front and rear.

I went with '87-'93 V8 Mustang spindles, 73mm SVO calipers and slotted rotors up front while the back got North Race Cars disc brake conversion brackets and '93 Cobra/T-Bird rear discs and the MC/prop valve I mentioned earlier. I don't race the car but I have thought about trying an autocross event one day and I think with a pad upgrade and some better brake fluid things should be ok. I like the way it stops and the pedal feels good too.

BTW, the NRC brackets are setup for a stock rear track width which can be an advantage over the wider SN axle assembly depending on wheel choice or other factors. (Just another thing to think about.)

The wheel I ultimately chose is the '93 Cobra wheel (aftermarket). I think it looks great on Foxes of all varieties! Also, it's available in both 4 or 5 lug and are 8.5" wide (245/45/17) so I think they look pretty beefy.



Based on what you've written above, it doesn't seem that you've decided on any suspension upgrades yet. That said, there are some instances where you could wind up making a suspension choice that dictates a specific spindle or control arm so you might want to start thinking about your future suspension/k member/rear set up's just to keep from buying parts and doing labor twice.

No doubt there is a lot to consider.

[sopwith21]

Super helpful, guys. Many thanks.

I'm leaning toward a tested and proven suspension package. I'd rather use someone else's experience rather than reinvent the wheel. Maximum Motorsports Road & Track package is looking pretty convincing so far, and I think that would dictate an upgrade whether I wanted one or not. Which I really don't.

Then again, the potential to use SN95 GT brakes seems very attractive... big, more than sufficient for a lighter, earlier Fox, and readily available. Wheel choice is not really a factor for me because the Pony aftermarket wheel packages are just gorgeous IMHO. But the availability and reliability of the bigger SN95 brakes is A Very Good Thing.

[sopwith21]

Two additional thoughts:

1) The 85 GT above is Most Noble And Righteous.
2) Tx again - downloading these details to pass along to my restoration shop. I'm more of a "he's done it before, let's ask him" guy than a "nah, I'll keep trying things myself til I find something that works" guy.

[erratic50]

If you're building a nice classic to drive you really can't go wrong with the foundation of the 1993 Cobra ride and handling. It's a lot less inexpensive than most other options and it is very effective both on the street and at the track.

Ford did a good job on both the street and race versions of the Cobra in 1993. But make no mistake - I would not volunteer to drive a race setup any distance on the street.

Yes Maximum Motorsports makes packages that will absolutely annihilate the factory SVO and Cobra setups..... but what are your goals? Get out your checkbook!

Im very happy with the stock shocks and struts under my 86 that I lowered 1.5" via X2's and caster/camber plates in front and slightly shortened 4cyl springs in the rear. I'd do the exact same thing again and my only regret is not doing it about 20 years sooner.

[Patrick Olsen]

5 lug reasons:
wider wheel selection
bigger brakes - 12" 99-04GT or 13" 04 cobra

Good summary of the 5-lug vs 4-lug points. One correction - the '99-04 V6/GT brakes are still 11", they just use a bigger/better caliper than the '94-98 cars.

[erratic50]

Yea, 10.87" is the measurement on the 99-04 GT rotor. I stand corrected.

Had to lol lol because that is what's on my 86GT.

They require a larger wheel than the older generation brakes - if memory serves measurements showed they would narrowly fit inside a 16" wheel. I do know they look plenty large behind my 17" rims. They work quite well with drilled/slotted Baer rotors and a great performing pads.

[vintageracer]

5 Lug

[srad2drag]

There is a guy on the corral selling a Baer 4 lug big brake setup front and rear. 12 inch rotors also.

[erratic50]

Any part numbers on that setup? Afaik they made a nice piece back in the day. The one concern I have is wheel size. A 12" rotor will clear a 16" rim but unless the calipers are something I'm not envisioning they won't clear a 15". Heck my setup with dual piston 11's won't clear a 15 for what it's worth.

[Nation]

That Baer setup will soon be in my garage ��

[Hammer Down]

I have 87up front brakes with hawk rotors and hawk hp+ pads and the pedal will go to the floor after less than one lap of hard driving. You'll have to baby it to make those last. My rotors were cracked and pads crumbling after one OTD. They were fine for the street but if you try autocross or track I'd go at least 13" brakes. Although that Baer 12" 4-lug setup sounds really cool.

[sopwith21]

Ford did a good job on both the street and race versions of the Cobra in 1993. But make no mistake - I would not volunteer to drive a race setup any distance on the street.

Yes Maximum Motorsports makes packages that will absolutely annihilate the factory SVO and Cobra setups..... but what are your goals?

This is absolutely intended as a street car. A high performance street car that will be driven hard and might see occasional autocross/track day duty, but a street car nonetheless. I spend all summer behind the wheel of a race car, and the last thing I want is a true racing build. Yikes. I want some comfort with good street performance.

Is Ford Performance the best place to start researching a possible 93 Cobra setup? Would be nice if it was available as a package rather than piecing it together.

[srad2drag]

Any part numbers on that setup? Afaik they made a nice piece back in the day. The one concern I have is wheel size. A 12" rotor will clear a 16" rim but unless the calipers are something I'm not envisioning they won't clear a 15". Heck my setup with dual piston 11's won't clear a 15 for what it's worth.

I have that kit on the front of my 93 gt and it clears my 15 inch weld rts wheels with a 3/8 spacer.