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I have put a TCI IFS under my 48 GMC truck. The springs have not started to compress yet & all the weight is on the truck. If I stand on one frame rails & jump up & down the spring still does not compress.
I can take the springs out , cut 1/2 a coil & reinstall,but maybe I should just go to 4cyl springs.
Does anyone w/a Must II IFS in there truck have any advice?

thanks Don

Hi weldvair - TCI usually sells a coil spring with their kit that is too high a spring rate. My buddy has the TCI IFS in his '52 Chevy 1/2 ton. The springs that came with the kit are 450lb spring rate. You only need a 350 lb spring rate if you are running a small block Chevy engine with either TH350 or TH400 tranny. The front end will never settle down with those springs you have. My buddy cut one coil out and it brought the front end down so that the lower control arms are parallel to the ground, which is what you want.

Don..... Cutting springs is the cheap and easy option,but certainly not the best.
Don't get me wrong,I've done it myself.(It ruined the ride in my old Vauxhall Cresta) It looked cool tho'!
The problem is,it will affect the spring rate and also ride quality. Most spring are designed to be progressive through their compression range,cutting will affect this.
Save your $$$$ and buy a pair of the correct springs.
You know it makes sense! Your truck will thank you for it.
Why don't you contact TCI and see what they suggest?
Good Luck
Jock.

Jockbolter50 - TCI kind of leaves it to the customer to chose the spring. I've used Must II IFS kits 4 times w/cars lighter than the 48 trk & I've used 4 cyl springs with 1/2 a coll cut.

This time I got 6 cyl springs & It sure seems like they will be to heavy even w/a coil cut.

Don

I agree with Jock and weldair. I prefer not to cut a coil unless there is no other option. I think the 4 cyl coil spring will work in your '48 1/2 ton truck. The two things to keep in mind are spring load and spring rate. The spring load is what keeps the front end of the truck up. Your truck with small block Chevy motor and TH350 tranny will have in the neighborhood of 1600 lbs of weight on the front end. And as I said previously a 350lb spring rate should be fine. If you can get your hands on a MOOG coil spring book you can look up the spring load and spring rate for '74-'78 Must II and go from there as a reference point.

Don I had the same problem with my '46 Panel when I was building it. You really do need 350 springs don't cut them. I thought the 350lb springs were to much. You really didn't say how far along your truck is but what I did with mine was to build kinda of a fake shock with 1/2" threaded rod and a short piece of pipe to take the place of the shock. I compressed the springs down to level the lower control arms(ride height) and left them till the very end of the build. By that time the springs were completly "settled" and I've no problems ever since. I am also running a 350 sbc and TH400 so really go with the 350's you'll be much better off.

I started out with original springs that came out from under a V8 Mustang. Being used I thought they were a little weak and thougth one was weaker than the other. I then bought a new set through Advance Auto ($60) and installed them. The truck (37Pickup) still rides and drives very good.........just info, hope it helps in some way.

When I put the TCI unit in my 55,I cut one coil off of the springs.It has worked out very well.Without cutting the one coil off I could not hook up the shocks.Soon as you get it assembled get it to a good frontend shop for an allignment.

As far as 4 or 6 cyl.springs???When I bought my kit from TCI the springs were included,there was no choice of springs. Although this frontend is referred to as an M2 it is actually all made up by TCI.It has been several years,but if I remember right there was a choice of standard or dropped spindles.

Here's a link to part numbers from NAPA for the MII springs:

http://www.fatmanfab.com/catalogpage.php?page=34

OK -Coil spring info here. Probably more than you want to know. The link from Desert_buick to Fatman provides Napa part numbers. Here is the break down including Napa part number/spring load lbs./spring rate lbs./ year and engine of MustII.
#277-3036/ 1388/353/'74-'76 Must II &'78 Pinto wagon 6cyl
#277-3037/1265/324/ '78 4cyl
#277-3038 / 1561/364/ '74-'76 4 cyl & 6cyl

Coil spring info continued from previous post.
#277-3039 / 1400/317/ '77 4 cyl & 6 cyl

Chuckthetruck - thanks, thats the info I needed. Mine were 350lb/in so they should be fine. I'll cut a 1/2 coil next week
& see if that drops the ht. I also noticed the the steering is very very hard, thus the ball joints are binding. hopefully dropping it down will free them up.

Thanks Don