2/4 or 3/4 Drop Kit, what size tires for Rally 15"s?

[NightRunner]

As the title states, I'm doing a 2/4 or 3/4 drop, not too sure which one yet. Still weighing the pros and cons of a Spring vs. Spindle drop. I just wanted to see what the guys who have ran a similar set up went to for tires size wise. I know the S10 guys have a whole chart dedicated to drop to tire size ratio on their site, haven't been able to dig one up like that on GMT400's yet.

Any advice is welcome, thanks!

 

[Oldblue98]

As the title states, I'm doing a 2/4 or 3/4 drop, not too sure which one yet. Still weighing the pros and cons of a Spring vs. Spindle drop. I just wanted to see what the guys who have ran a similar set up went to for tires size wise. I know the S10 guys have a whole chart dedicated to drop to tire size ratio on their site, haven't been able to dig one up like that on GMT400's yet.

Any advice is welcome, thanks!

I have 8 inch truck rally's front & rear on a 4/6 drop. with drop spindle and drop springs front and flip and c notch rear And run 235/70/15 front and 255/70/15 rear. Both front and rear fender edges rolled up. Clears fine front & rear

 

[ima93chevyguy]

I've always heard to go the spindle route because it's the "better" way because you're not actually changing the suspension such as with a spring kit... I run a spindle, hangar, shackle 2/4 and don't have any problems other than the shackles hit the bed on bumps because step side. Spindle is more expensive also. I also replaced all 4 shocks with belltechs
Rides really good, would almost ride better than it was before if the shackles didn't hit, which i need to get under there and take care of it.
I run 255/55/r18 so that's 29 inch diameter which the best i remember is really close to stock tire size..
All i did was roll the front fenders because my tires would hit the edge on bad bumps, which ironically Mississippi is full of.

But as long as you keep your tire diameter around 29 inches you should be fine.

 

[NightRunner]

I run 255/55/r18 so that's 29 inch diameter which the best i remember is really close to stock tire size.. All i did was roll the front fenders because my tires would hit the edge on bad bumps, which ironically Mississippi is full of.

Did you have any issues with your Rally wheels rubbing the drop spindle? I've seen that some people have a rub problem with them and I'm looking to avoid that. Definitely don't want to cut into my lower control arm if I don't have to. I'd rather spend the extra $60 and buy the DJM Caltrax Control Arms vs. Spindles if I have to modify to fit.

 

[ima93chevyguy]

Did you have any issues with your Rally wheels rubbing the drop spindle? I've seen that some people have a rub problem with them and I'm looking to avoid that. Definitely don't want to cut into my lower control arm if I don't have to. I'd rather spend the extra $60 and buy the DJM Caltrax Control Arms vs. Spindles if I have to modify to fit.

No rubbing issues, could be because they're 18's or could be my spacing. Idk.

My offset is 0mm and my backspace is 4.5". I'd have to look but I don't think it's real close to rubbing.

 

[sewlow]

The modification to the LCA does not require cutting. Just some slight grindage.
The mod has been done 1000's of times over the years since people (Boyd Coddington) first started lowering these trucks, w-a-y back in '88.
I have never heard of a catastrophic failure due to this procedure.
My '98 (black) has been modded in this way for over 10 years.
My '97, 5 years.
With the stresses that I put my trucks through in the corners, if there is/was a weak link, I will find it (HeHe!) ...& have! The LCA mod has never been a concern. Yes, I kept an eye on the '98's when it was done for the first couple of years. No cracks, no bending, no warping of the arms.

This is all that is required to do.
Turn the wheel to the lock & then measure approx. 1.75"-2" in from there.
Do both sides of the LCA.
That extra measurement is to allow for a bit more clearance when the suspension compresses.

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[NightRunner]

Okay, that definitely makes me feel a bit better about lowering. Definitely something to keep in mind.

 

[sewlow]

The issue of the wheels rubbing the LCAs is the reason why BellTech, the first producers of dropped spindles, designed their spindles to move the track width out about 1/2"-3/4".
Back then, a 17" wheel was considered BIG.
Other manufacturers have copied B/T's design, retaining that off-set.
More recent, later designed spindles do not move the wheels out.
DJM & (IIRC) McGaughey's are the ones to look for, if that wider track width is of a concern. There could be others.
The spindles on both of my trucks are from a Co. by the name of CMS.
Canuck Motor Sports.
A B/T derivative. Only reason I bought these is because their main distribution point for all of North America is local. Like...20 minutes away.
Shipping costs of ANYTHING from the States, along with the exchange, duties & fees with the taxes added on top of all that can add up very quick!
An hour of my time & the fuel to do the round trip is a lot less expensive!

 

[Dave454ss]

Timely thread...been debating much the same myself (C5 Vette Wheels Planned for mine)...one thing I'm not seing discussed here are the drop Control arms like whats available with the DJM Kits..

In relation to rubbing issues...why would we want a spindle vs the Control arm?

 

[sewlow]

I've never had any personal experience with drop LCAs.
From what I've gather, there is nothing wrong with them when used on their own.
It's when they are combined with other methods of lowering is when they start to cause issues.
The deeper pocket for the spring becomes the lowest point when used with drop spindles. So, ground clearance is even less than with a spindle/spring combo. Lowering creates enough probs to begin with. Why add to the situation?
Drop LCAs with drop springs creates camber/castor/bump steer issues for your alignment guy.
Along with those same ground clearance probs.
At least, those are the probs that I've learned from hanging around here over the years. I'm sure there are members with more info in this area that could pipe in with actual experience.