74 c10 mcgaughys and cpp

[Greensweets]

Hey guys ok when I lowered my 74 I used cpp 2.5 spindles and mcgaughys 2" drop springs well I have still a 275-75-15 tire up front so when I took it off the stands,the truck sat so low the fender tubs sat on the tires and couldn't roll. So I took my stock springs and cut a half coil and installed back in and it sits great with the tall tires,that was temporary,now I just got in my mcgaughys 1" drop springs which are the same length just stiffer spring steel I guess. My concern is before I put these new stiffer springs in is it gunna drop down so low again it's gunna sit on the tires? Now the front tires will be 235/60-15 soon but I mean for now? Has anyone used this same set up from cpp and mcgaughys and had this same issue?

 

[smoothandlow84]

I am usung McGaughy 2" drop spindles and 3" coils for a total of a 5 " drop. When I had the 15" steel rally wheels and tires (sorry, dont recall the tire size)....I had approx 3" of spacing between the inner fenderwell and the top of the tire. I have since removed and fabicated custom inner fenderwells and ditched the 15" rally wheels for 20" alloys. It sounds like you may have received the incorrect spring rate for your application. For example...if you have coils for a inline 6 and install them in a truck with a v8...your spring will be squatted. This is what happened to me back when i was building my s10. The coils I received were for a 4 cylider s10...when I needed coils for the v6. Therefore instead of a 2" drop....it was more like a 5".

 

[MikeB]

I've read on more than one forum that McGaughy 1" drop springs are closer to 2" than 1". That's at the wheel, not at the spring.

Hard to say how much lower than stock the truck will sit with those springs, depending on which springs your truck has, and whether or not they've sagged.

I was researching springs just earlier today, and Moog's catalog shows the standard spring is #6452, regardless of engine. They show #6454 is used with HD suspension -- again, regardless of engine.

Later year trucks with big block and diesel used the #6454 as standard.

 

[smoothandlow84]

I've read on more than one forum that McGaughy 1" drop springs are closer to 2" than 1". That's at the wheel, not at the spring.

Hard to say how much lower than stock the truck will sit with those springs, depending on which springs your truck has, and whether or not they've sagged.

I was researching springs just earlier today, and Moog's catalog shows the standard spring is #6452, regardless of engine. They show #6454 is used with HD suspension -- again, regardless of engine.

Later year trucks with big block and diesel used the #6454 as standard.

Maybe between a 305 and a 350, but I seriously doubt the same coil is used for a inline 6 and a v8 due to the different weight. I have McGaughy coils and spindles and both were accurate as far as the ride height. I would reccomend calling tech support at McGaughy.

 

[MikeB]

Maybe between a 305 and a 350, but I seriously doubt the same coil is used for a inline 6 and a v8 due to the different weight. I have McGaughy coils and spindles and both were accurate as far as the ride height. I would reccomend calling tech support at McGaughy.

I was just passing along what the Moog catalog shows for 1974 trucks.

Factory specs for my 82 C10 show a standard spring at 1475#, with optional HD springs at 1625# (manual brakes) and 1700# (pwr brakes) regardless of engine.

So, one of the stiffer springs would seem to be installed only if the HD spring option was specified.

BTW, I can tell you that my truck sits no lower in front with a 355 than it did with its original 250 six. I'll have to find a picture of it when it had the 250, but here's what it sits like now with the same springs. Not exactly sagging!

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[smoothandlow84]

I dont know...maybe it was just the case with my build. Hell....I just discovered that I have hd front brakes based upon the larger inner bearing on the rotor. I just ordered and installed cross drilled and slotted rotors and initially, the supplier sent me the standard half ton rotors which require a much smaller inner bearing and race.

Oh well....at least I have confirmed that I have the upgraded hd rotors, and brake system which is usually found on suburbans and diesel versions.


Needless to say this build has led me to some interesting discoveries for sure. Im still not 100 percent convinced about the spring rates / engine size discussion. From all the other truck builds from mini to full size, I have always made sure to specify when ordering springs what engine in installed.

McGaughy's customs is just down the street from my business and they are my go to shop for technical advise. I am just going off of what they told me when I ordered my springs for my square. I was told there was a difference at least with their coils. My square originally had a six installed and it was swapped out for the 350 during the course of my build along with the transmission and drive train.

 

[MikeB]

Im still not 100 percent convinced about the spring rates / engine size discussion. From all the other truck builds from mini to full size, I have always made sure to specify when ordering springs what engine in installed.

McGaughy's customs is just down the street from my business and they are my go to shop for technical advise. I am just going off of what they told me when I ordered my springs for my square. I was told there was a difference at least with their coils. My square originally had a six installed and it was swapped out for the 350 during the course of my build along with the transmission and drive train.

I hear ya. Maybe the "standard" spring was rarely if ever used with a V-8. Sometimes the factory even made changes in mid-year, and more than likely made changes between 73 and 87. And the two Moog springs might only be "in the ballpark" replacements.

Gotta wonder if McG's 1" inch drop spring is in comparison to a std or HD factory spring, and with small block or big block? Instead of "1" drop" a more useful spec would be "fender lip to center of spindle" with truck sitting on the ground. That eliminates guessing at what spring you have now. I seem to remember a guy on a 55-57 car forum doing that for 3 or 4 different springs. Very useful.

 

[smoothandlow84]

I'll have to take a walk down to their shop and inquire some more on that topic...

 

[MikeB]

I'll have to take a walk down to their shop and inquire some more on that topic...

I'd appreciate that. I'm gathering parts to do a front suspension & steering rebuild and would like to drop it 1"-2".

I'd go the 2.5" spindle route, but don't want to worry about wheel to spindle clearance with my 8x15 rally wheels with 4.5" backspacing. Also, it looks like I'd potentially have tire-to-fender lip clearance issues since McG's says their spindles locate the wheels outward a little (forgot the exact amount).

 

[RThiel]

I have McGaughy's 2.5" spindles, 1" springs (I did the same thing you did, had 2" springs and couldn't move), and 255/60 15 tires and have no major issues. You'll need to remove some of the lip on the LCA where it rubs the tire, And depending how wide you go you may need to roll fender lips.