[BLstangin]

O.k. I decided on the combo I think for the new motor, it'll be a dart 4.125 bore block and a 4" stroke for 427C.I. Anyway I got a smokin deal on a set of brand new afr 205 heads that have been professionally ported and polished, ferrera exhaust valves, titanium retainers and .740 lift solid roller springs, brand new. The guy that had them couldn't get them to flow enough. He was gonna use them to try and make 1000 horsepower with boost. I'll be getting the flow charts with them, but anyway, now this thing should be capable of 550-600 hp with a custom cam and a well designed combo. It's a 100% street car that is just a toy and I just want to make it fast because I can and tough so I don't break it right away. So it will have to be streetable and I don't want to cage it. The frames, floors and torque boxes are all solid and straight, I have a monte carlo bar and one piece export brace in it, but will a set of maier or likewise subframe connectors welded in be enough to keep the body from twisting? Shouldn't ever see and really hard lauches I don't think, as it'll probably have street tires or drag raidals on it. What do you guys think?

 

[F15Falcon]

One of the things that people forget about the uni-body designed cars like a Mustang is that they are basically a monoccoque chassis, with the exception of a stressed skin. This is the design of chassis that is used in most airplanes, as well as alot higher forms of racing like IRL, and formula one. The rockers on a uni-body are pretty stout and do their job well. Even with out a rollcage, the stiffness provided by the stock uni-body chassis is very good. Most six point style roll bars do little to provide additional chassis stiffness because they do not attach in the right places, and because there are too few attachment points. So yes, I think your chassis will handle the added HP with or without the connectors.

 

[1 Bad 88 GT]

As an aside, the only reason to not get 1000hp out of those heads on a blown engine is because he didn't know what he was doing. I've seen box stock 185's on a single turbo'd 331 make over 1000hp.

 

[BLstangin]

Well he had almost $3,000 in recipts for them and sold them to me for just over half that, and is sending the flow charts with them, and the pics looked like what he said they were, I just want to make sure that the body panels don't get that ripple effect from twisting the chassis, and I don't want it to permenatly twist it, and I plan to put cal-tracs on it someday. So you guys relieved some of my worries there. I've been told I should be able to make about 600 hp. I'd be tickled pink if I could bet 425 to the rear wheels!

 

[82GT]

With power like that, I would definatly get subframes. I don't care what anyone says...subframes are a good idea on even a stock mustang.
In your case, since you don't want a cage, I would at least get the subframes that pass through the floor pans.

 

[Is1BadFord]

I think, unless you're gonna be running tires that will literally break loose if you take a deep breath, you can say goodbye to your windshield. My buddy and I built a 429, nothing serious, but plenty of torque, and put it into a 67 coupe. Torque strap, welded subframe connectors, full shock tower bracing, and a bolt in 4pt cage. First hard jab of the throttle with 295/50/15 BFG's, and the windshield cracked lol. Best part? The tires were spinning like mad the whole time. These cars chassis, monocoque or not, weren't designed to handle 550-600lb/ft of torque, without serious bolstering. He might have had a chance of keeping his windshield, if that cage had been welded in, and tied into the frame somehow instead of the rocker areas, but even then, I doubt it. I've seen this happen more times than I can count. As a matter of fact, one of the ways we used to tell sneaky street racers that had any power around here when I was a kid, was a busted windshield, from the corner up.

Just my 2 cents.

Cris Anderson

PS
I busted the window in my first 67 coupe at the drag strip with a nasty, nasty 306, on slicks. They just aren't made for those kind of stresses =).
C.

 

[Redneckracer21]

I've got a set of the Maier racing subframe connectors going into my 67 stang right now and they are nice pieces. I've talked to many many people who say that the older unibodies are about as strong as a tin can. After crawling over every single inch of my car i realized exactly what they were talking about. The subframes are a VERY good idea.

 

[igo1090]

put a jack under the lf lower a arm and lift. if you think that is a stiff frame, keep dreaming.
yes sub-frame connectors, and tie the roll bar into them or the oem subframe. 2 rearward bars should meet frame rails near the upper shock mounts.

 

[Sonny]

My own made connectors go from the engine crossmember -steering gear-trans cross member-front rear spring eye-rear shock top mount.That way most of the other side members tie the two sides together.I also have a cage in the rear for the panhard and a 3 point strut to firewall mount up front.I don't believe its enough but it made a huge change to adjusting door hinges after hard suspension etc was installed. A cage would be good for you but COMPUTER design it to the stress points in YOUR type of car.Every model of car is different.
Andreas

 

[F15Falcon]

He said that it is a 100% street car, so that means he will never hook it up to break anything, all a street tire is going to do is spin.

 

[2FST4U]

Drag radials qualify as a street tire too.

 

[BLstangin]

Ya, I really do not plan to take it to a track, just run 295/50r15 tires on it or a drag radial, if I do take it to a track I would just ease off the line some to keep from shocking it. I just want it to be fast, but I don't want it to twist it up, there's lots of people out there running big motors in these cars so there has to be a way to keep them from twisting, I was just wondering if you guys with big block strokers and such were doing anything other than just subframe connectors, or not? It's a good disscussion though. I just wanna make sure the chassis will take it, but don't want to put a cage in it, so is there anywhere else I can strengthen it, and will the rear leaf mounts hold up fine, or is there a way to modify them, I want to put cal-tracs on it so that should help with traction some, but probably not enough.

 

[mustangboy]

My brother had a few pretty stout big block motors in his 69 Mach 1 with a 4 speed and 4.11s.The chassis was totally stock but he used to speed shift it at 6000 rpms all the time with no chassis problems..Mind you this was back in the early 70s when there weren't really any sticky street tires.I think you will be ok as long as you don't get it too hook up very well.

 

[Is1BadFord]

Drag radials WILL hook up lol. And like I said, my buddy popped those windshields with 295/50/15 BFG's. Not very sticky. I think the 69/70's being heavier cars will work in your favor, they were made for big blocks. For some reason I had in mind that you had an early bodystyle. Not sure why. Anyhow, good luck, and let us know what happens =)

Cris

 

[Goneinsixty]

Drag radials WILL hook up lol. And like I said, my buddy popped those windshields with 295/50/15 BFG's. Not very sticky. I think the 69/70's being heavier cars will work in your favor, they were made for big blocks. For some reason I had in mind that you had an early bodystyle. Not sure why. Anyhow, good luck, and let us know what happens =)

Cris

I know this thread is ancient. But how the heck did you fit 295/55r15's out back on 67 Stang. I though 275/50r15 was largest you can go with rolled lips and metal sticking out by bumpstop removed.

 

[DanH]

I know this thread is ancient. But how the heck did you fit 295/55r15's out back on 67 Stang. I though 275/50r15 was largest you can go with rolled lips and metal sticking out by bumpstop removed.

I have no idea what the inch size of street tires are .

think a 67 is a little narrower than the 69 stang . with the stock frame rails , bump stop removed a 11.5 wide with a 5"b/s tire fits inside lip

 

[Mroldfart2U]

it'll have that 80's vibe goin on with out other mods for sure.... and yeah the connectors are a good idea, strip use or not...

 

[redtail]

I have no idea what the inch size of street tires are .

think a 67 is a little narrower than the 69 stang . with the stock frame rails , bump stop removed a 11.5 wide with a 5"b/s tire fits inside lip

X2 even the little falcons in 68-69 could fit 11.5-12 wide in the rear. had some on my car.