I am not a big fan of having my bodyshop hack-up my floor pans but after speaking with several people about my setup (525hp 455, Tremec TKO-600 5 spd, Ford 9" with detroit locker and 3.89 gears), everyone suggests I us the subframe connectors that came with my car. It will be a pretty knarly street car, but I do not plan on taking the car to the dragstrip or ever putting slicks on it. Everyone also seems to recommend the weld-in connectors vs. bolt-in. The connectors that came with the car are Chris Alston's Chassisworks and they are pretty substantial:

http://www.69firebirdbuild.com/albums/album_image/3618178/1043075.htm

...they require the rear floor pans to be cut. The good news is, you can't see them once they are installed and they are supposed to be very effective.

My question is, does anyone have similar connectors? Do you have pics of your's installed?

Thanks,

Poser

Mine are cheap CE bolt-ins but I can snap a pic easy enough if you think it will help. Mine's a 69 coupe.

Robert

Bolt on work great as long as you do it right. I've run 500 HP with bolt-on with no body contortions. There is no need to be cutting up your floors. If you are dead set on welding there are some nice weld-in connectors that don't effect the floors. The difference is they are curved where the ones you have are straight.

The DSE connectors require cutting the floor, but if it is installed carefully, it will look like a factory job. I've read that the cars vary, and the template can cause you to cut your floor in the wrong spot. So if you're going to cut your floor to let in a connector, take nothing for granted and make your own measurements.

The Hotchkis round frame connector doesn't require floor cutting.

There are other choices out there that don't require cutting your floor. Some weld, some bolt up. Some can be modified to bolt up those designed for welding.

The DSE looks very nice, but its a big decision to cut into a factory floor.

At that HP level, you need some sort of connectors. I've seen stock birds with stress cracking in the quarter. Five hundred plus horse is bound to tweak the car if you hook up and have no connectors.

I to have the CE bolt-ins no prblems yet. I do run 10" slicks about a dozen times a year. I did lunch a converter. Bill

Thanks guys. I have been doing quite a bit of research and I think I want to stick with the weld-in style. My body has been floor panned and quartered, so I am worried about stressing it and I think the weld-ins will give me more rigidity.

The DSE's make a lot of sense...I like how they contour to the floor. I think I will speak with my bodyshop and see what they are most comfortable with (DSE's vs. Chassisworks).

Poser

Take a look at the installation discussion for the DSE connectors at

http://www.pro-touring.com/forum/showthread.php?t=7917

Be sure to alert the shop about the template issue. A few guys reported cutting the floor and later on finding they had that slot off-center by 3/8" or so. That meant they had to cut 3/8" more from one side and patch back 3/8" on the other. That would be pretty annoying.

If you put these in, please post photos. I'm still deciding about this upgrade.

Make sure you save all your original parts,,,er...ah...chunks.

Ebay, NOS Firebird floor pan bits.

In the last 2 years I have owned at least 6 1st gens that have been either 'back halfed' or 'roll caged'. I'm telling you that the tears are not even dry yet! I know that there is nothing I can say to talk you out of cutting up your cars. I just wish there was.

I hear you Jim. But with 525 HP, the car's gonna get tore up anyway if you don't beef up the structure. You've had quite a few birds. Did any of them have tears in the quarter or have any body twist? I ripped the right rear torque box bolts loose in my 350/3 speed by 1972. I'm sure a more powerful setup will cause important damage in no time.

I'm still looking for a sturdy but not so surgical/invasive subframe connector that doesn't look like an iron bed frame stuck beneath the car. I hope to see the Hotchkis connectors in person before that decision needs to be made. I like the DSE kit except for it's surgical scars. Done well, it looks like a factory job.

I used to beat my cars real hard. 428's, 455's, big nitrous kits, no body rips at all. No slicks either though. Always bolt in frame connectors. I think that most of the cars that get body damage from torque have a weak part that is overlooked. Don't build torque monsters out of rusty/weak bodies.

QUOTE;"I'm still looking for a sturdy but not so surgical/invasive subframe connector that doesn't look like an iron bed frame stuck beneath the car."

I don't mind the square ones that you can see. They give you another place to use the floor jack or jack stand. You need to put traction bars on there anyway. You are going to notice the traction bars so what difference does it make that there is a frame connector showing a tiny bit?
To address the bolt in versus weld in. If you drill the holes very close to the diameter of the bolts, use two on each end, use the correct fine thread bolts the right way, bolt in work just fine.

Mine are square tubing notched to the floor pan, welded in front, welded to the convertible cross brace, bolted and welded in the back. It makes for a very firm chassis, especially for a 'vert. It is not visible unless you lay on your belly next to the car, or if it's in the air.

Hey Jim, I totally understand where you are coming from and I have no desire to hack-up a 37 year old car. This is not going to be a back-halfed, caged, or a mini-tubbed car. That is what I would consider "cutting up" a car. You have to underdstand it from my point of view. The car has qtr patches on both sides and floor patches on both sides. This alone has weakend the car from its' original state. Throw in 525hp up front and I am sure you can understand my concern.

Believe me when I say that the car will be done very tastefully with the interior returned to it's original condition. The frame connectors will not be visible. I am not crazy about having to put them in...but I also have no desire to drop $30K+ into making it a really nice car only to see a quarter panel patch pop or a pillar crack the 1st time I get on it.

Poser

Hey Poser,

Your own words: "It will be a pretty knarly street car, but I do not plan on taking the car to the dragstrip or ever putting slicks on it."

Sounds tame compared to what I put my bolt on subframe connector cars through. It's your car, go for it. There are many other readers that may want to hear an opinion that there is no reason to use anything more than a bolt in connector.

Vikki, can you post photos of your subframe connectors?

Sure. They were done by a previous owner around 1982 so I don't have the details, but they look just like a commonly available coupe model, with an additional notch. They don't affect the spring perches at all. One suggestion: change the body mounts to poly before installing welded subframe connectors. :rolleyes:

Just curious, what do the car show judges say about this type of mod? Do they ignore it to look and see if your clock has the correct movement? It looks really nice and sturdy. Would this modification make it wrong to call the car 'restored' when it's all done?

I register my car to show as modified, not restored. I also have rear seat speakers in the well covers, a TCI trans pan, a quartz clock movement, radial tires and an open element air cleaner. Hagerty Insurance still classes it as stock.

The Le Mans went through tech lines classed as "restored" because it had been repainted, although though it had radial tires they were never held against it.

Thanks for posting pics!

Poser

Vikkie, that looks very tidy.

Jim, if the car has frame connectors, they toss your butt out! Well, no not really, they put you into the modified catagory. There, judging would depend on the workmanship quality and design. At the recent show, they put people who had great looking cars with period correct Cragers, but not original Rally II's into a separate area. So yeah if you're going for awards in the restoration class, this modification, regardless of welded, bolted, or cut into the floor is going to exclude you from the winners circle.

What about swapping to a 12 bolt posi to take the power? Is that as unacceptable as having a Chevy motor? :rolleyes: Golly those are hard to look at.

QUOTE "What about swapping to a 12 bolt posi to take the power?"

Another unnecessary part/upgrade. A 10 bolt BOP is plenty strong enough. Tried and true with 500+ HP.