M1008 leaf spring question

[2deuce]

It sounds like you just have to know which one of the 3 sizes is on your truck. I'm changing what I originally thought because I took a look at my truck and the eye to eye distance changes with the weight on it. So I would measure the top leaf. If you have the truck loaded and the spring is flat it would be easier. I think you can measure eye to eye if the spring is perfectly flat otherwise follow the curve.

 

[Cucvnut]

What are your concerns? You have the springs. Look on pirate for 52/63 spring swaps inthe chevy section.

 

[skysix]

Thanks for the pirate link

probably just overanalysing / overplanning but I am remote from the truck so can't just go eyeball stuff to see if it will fit and don't want to buy stuff sight unseen as it were without knowing it can be made to work without affecting something else later in the build. bad engineering habit I guess...

 

[Cucvnut]

the springs will work

 

[skysix]

Thanks CUCVNUT - but not so sure. Stacked them (dam heavy too) beside the originals. Would have to get a custom tank or a 16 gallon OEM due to the 62" springs now projecting 4" further forward. Or relocate the axel to the rear.

Then comes the rear mount - the brace for the bumper/pintle has bolts where the ORD hanger would have to. Likekly not a problem, just do that end first in such away that holes can be drilled through the shackle flip bracket in the appropriate place.

SO... Assuming I get a pair of OEM short (16 gallon) tanks I am all good - except having lost 8 gallons of fuel storage. No problem right? swap in a Suburban tank.

WRONG - about 4-6" too long. Looking for a Blazer tank to fit where the spare used to be - has anyone tried that mod? The skid plate I test fit seems to be about 2" too long. Might work IF a new cross brace could be built that could be located about 3" further aft.

 

[Cucvnut]

Blazer/Suburban fuel tank crossmembers in K30 frame? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Thats a link to a blazer tank swap on a k30 frame.

 

[skysix]

Sweet - so it looks like I need to locate some Suburban cross members then modify the rear one - adapting the ends to fit the Pintle braces, and the front one to get the tank level. Diff clearance is gonna be tight thanks to the CUCV rear bumper/pintle bracing system... Then I'll have to locate a straight dual tank box and add a third filler door on the drivers side - probably take the one from my beat up military box... Seems like the work will be easier with the box off anyway. I'll try to get pics for future CUCV builds.

I am planning to use the 31 gallon Blazer tank for 71 total. Both side tanks to have diesel appropriate in-tank transfer pumps pushing to the rear tank using an extra blackout switch to select side/side. Extra size of the rear tank means can start pumping when hit 1/4 and not overfill. Fuel return lines back to originating side tank. Possibly an extra switch added to the rear sender to break the transfer pumps (both) power supply if full. All tanks vent lines ganged together then via a 1/2" hose to a single high point (top of box between the walls of the box with a one way valve in case of rollover - likely the right rear corner stake pocket area). Fuel gauge to rear tank only. Indicator lamp for pump operation adapted from a M35 instrunmment panel light with no lens cover - 12v bulb and diodes so one bulb for two pumps. Mounting switch/bulb in general area Civilian trucks have their tank selector rocker switch.

Many moons from now when I win the lottery (or have my own welder) I may have custom oversize tanks built which could up the capacity to 110 to 130 gallons using the space between the driveshaft and the right frame rail as well as a solid connection under the rail to the normal tank location (with a 1" or so deeper outboard tank). Also taller by 1" after body lift. Check out the NorthWest Metal Products right side aux tank: 42 gallons not including the extra inch at the top. 27 for the oversize left sidesaddle and 43 for the rear Blazer tank. Add 1" to all and I hope for 120+/- (110 + 10% for a reserve). IE: 2 drums per refill so a M101 trailer could easily bring along 2 complete refills with a low center of gravity for those long low-range runs offroad. Should give a range of about 1200-1500 miles round trip (hopefully 3000 total offroad range if I can average 8.5 mpg in the mud etc) $600 per truck refill in the area I plan to be exploring...

 

[Cucvnut]

That's a lot of fuel tohave the 6.2haul.

 

[skysix]

About 900 pounds including the tanks. Truck can haul a payload of 4000# so leaves 3100# for the box, people and a camper. Not planning to add that much!

 

[highsiera]

sorry if I missed it in the above posts, but is the eye to eye measuement on the stock m1008 rear spring 56"? are they 8 leaf or 9 leaf packs (not counting the big bottom leaf)? Asking because I want to replace the worn out rears on a 79 k35. BT