IRS question

This is for guys that know there IRS ( independant rear suspension) I got a 91 tbird that came with the factory 5.0 but im not sure which model b/c i chucked all of the emblems b4 thinking about it. I'm goin to dirt track this car so I had to gut everything and weld together a cage and what not. Now to the question I've never seen another dirt track car with the irs and theoretically it should handle better so do they break alot or something? If you have slid into something and broke a control arm or cv joint let me know so I can figure out in advance the things that are goin to brake to reinforce them now hopefully.

I forgot to say Im not runnin alot of power through it just a stock 85 302. Im tryin to gain speed through the handling and weight of the car its cheaper than building a badass LEGAL ford motor. Also what was the stock gear ratio for the 5.0 auto or more importantly are there any descent places to puchase differant ratios.

Stock gearing depends, I'd guess it's got a pretty highway friendly gear. AFAIK the highest (numerical) ratio gearing you could get was 3.27:1. Try US gear or Randy's ring & pinion for gears. Summit or Jeg's should have them too. As far as the IRS's durability, it's plenty strong. You could reinforce the control arms if you wanted to, I don't think it's necessary, just added weight. Also, you will probably wish you'd have gotten a solid axle car untill you get yours dialed in.

Personally im looking for something closer to a 3.08:1 so I dont have to shift Im runnin 1/5 mile track so first gear is where I like to leave it. I guess I'll find out when I take the differantial cover off. Im not to worried about the arms i was worried about the axles b/c we bump and bang alot.

The axles are plenty strong. Look inside the door tag and post the axle code, then we'll be able to tell exactly what ratio you have and if its open or limited slip.

ummm about that the doors have already been welded shut no to mention when I was skinning the drivers door it caught on fire and burn that stuff off but either way I have to remove the center sections cover and either find a spool that fits it or just weld the spider gears. Do they post the rations on the ring and pinion in that car or not?

If you're going to do all that, just cound the teeth on the r&p. Divide the smaller number into the bigger number to get your ratio.

It should have the count somwhere on the ring gear if its like most cars. I have already decided even if the car is the slowest one out there idc the fucker looks good lol. After she gets painted I'll post some pictures or try to atleast.

Ya kno... the IRS on these cars are strong. I slide sideways into a curb at roughly 45mph, and totaly destroyed my perfect late style Super Coupe wheel :banghead: . The rear end became slightly crooked, as it has a lot of camber. I shouldt say alot, because its barley noticable to the untrained eye.. so I can attest to the IRS strength.

The " Thunderchicken" is almost finished and ready for inspection and paint. Im just praying I can make up some lie as to why its in custom motor mounts. hopefully they dont notice or I can get away with it was a v6 car so i hd to get differant mounts. I have some pics but I cant seem to figure out how to post them.