The inner fenders on the Hiedts kits are now curved to match the cars fenders. I have few photos of my Heidts clip install at www.photobucket.com/albums/c231/62civa I have been really happy overall with the Heidts kit. TCI and a few others may be slightly better, but they cost more as well. Just my 2 cents.
The front clips are pretty similar, One of the deciding factors for me was that TCI narrows the subframe and uses narrowed control arms, ultimately allowing wider wheel and tire combo. On the Heidts coil-over unit they now have the down tube with the heim joints, thats pretty cool. Incidently I think everyone has the inner fender thing resolved by now.
The rears are quite a bit different I got my TCI unit in recently and it's pretty slick, the fact that the Heidts unit doesn't have a crossmember made the decision a no-brainer for me. I didn't want to do a mini-tub or move the frame rails so either kit will work well in that capacity, in fact I think both kits require stock placement of the frame rails. I also like the tranny mount and how it integrates with the subframe connectors also I like the optional sway bar that TCI offers for theirs, I guess Heidts offers a tranny mount but I know they will not be offering a sway bar option. I also like the brackets that TCI uses for the rear end housing, they go all the way around the axle tubes rather than on one surface. I took the liberty of including a link to some of the progress shot I posted recently, You can see the TCI front and rear....in captivity
What problems did you have with the TCI unit? I have sold many of these units with very few problems other than a instuction sheet with poor pictures. Let me know so I can relay the problems to TCI.
I bought my TCI fron clip through one of THEIR dealers, Stitz Street Rods. Stitz has gone out of business and did not get me all the parts in the clip kit (missing the sway bar, shims, grease seals, brake booster bracket, wrong caliper mounting plates for the Wilwood brakes).
I called TCI and they were happy to SELL me a sway bar ($300+) and the correct caliper mounting plates ($200+). They would not help me with the brake booster bracket or grease seals (told me to contact the mfgs of those items). They also said they have changed the design of their brake kit so I am stuck with a power brake booster (probably another $250+). They have sent me the wrong caliper mounting plates twice now and I plan on heading up to their shop to try to get the correct parts (my heart can't take the UPS guy showing up with a TCI box anymore).
So, I have had a very expensive experience with TCI and their interest in follow through with their customers seems really low on the scale.
I am trying to get to the point where I don't have to deal with them anymore but I do need their parts to finish.
You can probably guess what my recommendation is for using their stuff.