help with front coil spring compatibility

[tranz am]

Ok Im on the last stretch of my hunt and need to know if the coil springs for 67-72 are the same as those in 73-87. I cant seam to find a 3 inch drop spring for 73-87.

What am I doing?
Im working on a 69 gmc c15. My objective is to drop the truck 5-6 inches, convert over to power front disk and retaining the stock 6 lugs appearance for the lowest price.
I have converted the 69 front end to a 78. This utilizes the better bushings offered on the later pickups and gives me the all I need to convert to disk 5 lug. This is all great if I wasn't in love with the centerline 6 lug rims I already have.
So I did some searching and I have found a 6 lug rotor that will bolt to a 2 inch drop spindle that will accommodate my stock 78 backing plate and calipers.

[TN70C10]

where did you find the 6 lug rotors? details!

[70GMCer]

I would also like to know about those rotors you found. I've been told that the 67/72 front coils do fit in the later 73/87. I am planning on doing the same thing as you are, except that I am staying with stock height.

[Tx Firefighter]

Yes fellows, the 73-87 front spring is the same as 67-72. For a 3 inch drop front spring, I always use Summit brand springs. I believe the part number is Sum-G727 if I remember correctly. When you get the springs and open the box, you'll find that they are very nice "Ground Force" brand springs for an unbeatable price.

Second, the 6 lug rotors are available from any 67-72 vendor. The 6 lug conversion rotor that they sell fits any 1 1/4 inch truck spindle, whether stock or dropped.

Third, if you're looking for a 3 inch drop spindle, I believe the part number is BellTech BEL-3100. That's a 73-87 drop spindle set, 3 inch drop for 1 1/4 inch thick rotors. Summit has free shipping and they are heavy as hell, so that's where I always buy them. Beware though, the 3 inch drop spindle can cause backspacing issues, particularly with an 8 inch rally wheel. I always run a 7 inch rally wheel in the front if I run a 3 inch drop spindle. The 2 1/2 inch drop spindle is more common because they don't cause the backspacing concerns that a 3 incher does.

A 3 inch drop spindle combined with a 3 inch drop spring is not for the faint of heart. The control arm will set damn close to the ground and you will bend them if you drive without due regard. My daily driver is 5.5 inches in front and I've got to pay attention to entering and leaving parking lots.

[tranz am]

Very nice. Glad that it will work out for the three inch drop springs.

[mexgrhd68]

I've seen pictures and articles where they trim the bottom portion of the a-arm, I would say about an inch, then they go back and box in the arm for strength. helps with the spindle problem of rubbing on your tire when turning. might be something to look at.

[tranz am]

Hmm Id like to see that got any pics.

[mexgrhd68]

Tranz am, sorry I don't, seen this back in the day in some old issues of sport truck, just threw a whole bunch of those mags about 9 months ago, I had to move and didn't want to haul mags with me. sorry.