1988 Chevy Crew Cab build
#1
1988 Chevy Crew Cab build
Hey guys, thought I would share my build. Please bear with me as it will be a slow build (tight funds and truck is 35 mins away)
started life as lowly 2wd 1ton work truck with 350tbi and 4spd manual, previous owner converted to 4wd with axles,tranny and transfer case from 1/2 ton meaning weaker axles 3.08 ratios and a 700r4 AUTO.
first day I had truck I swapped the axles for a set I had laying around (dana 44hd front and 14bolt FF rear with 3.73 gears) and lifted truck 4" with used lift I also had laying around...along with 5 35x14.50x16.5 STA trailbreaker tires bringing truck to this point
started life as lowly 2wd 1ton work truck with 350tbi and 4spd manual, previous owner converted to 4wd with axles,tranny and transfer case from 1/2 ton meaning weaker axles 3.08 ratios and a 700r4 AUTO.
first day I had truck I swapped the axles for a set I had laying around (dana 44hd front and 14bolt FF rear with 3.73 gears) and lifted truck 4" with used lift I also had laying around...along with 5 35x14.50x16.5 STA trailbreaker tires bringing truck to this point
#2
drove truck for about a week and got bored with the gutless 700r4 3.73ratio and 35" tall tire combo (truck is really heavy)
so out came front axle,trans and transfer case,and springs
in went 52" chevy rear springs with AAL's, 2.5ton GMC front axle (with 6.17 gears), 5spd manual NV3500 trans and np241 transfer from newer body style 89 chevy truck... for now has 39" tall stock military 9.00-20 tires
2nd pic is with stock 4wd 2500 gmc so you can tell how much lift is on it
so out came front axle,trans and transfer case,and springs
in went 52" chevy rear springs with AAL's, 2.5ton GMC front axle (with 6.17 gears), 5spd manual NV3500 trans and np241 transfer from newer body style 89 chevy truck... for now has 39" tall stock military 9.00-20 tires
2nd pic is with stock 4wd 2500 gmc so you can tell how much lift is on it
#3
truck beside it is a 6.2L diesel truck that I am pulling motor from for this swap... I have hummer headers and a M90 eaton supercharger that i am fabbing intake for on top of 6.2... was going to turbo but with engines low rpm manners I thought the turbo would only be useful for very small rpm band...so super charged it will make boost at idle and top out at about 8psi perfect for slow revving diesel
also here is picture of tires I have for truck... they are 425/65/22.5 super singles from front of cement trucks
equal out to be about 43" tall 14" wide AT tire
using gear ratio calc program should be running around 2288 RPM @65mph PERFECT!! campared to a stock military chevy's 3288rpm @65 (th400.4.56 gears and 32" tires stock)
also here is picture of tires I have for truck... they are 425/65/22.5 super singles from front of cement trucks
equal out to be about 43" tall 14" wide AT tire
using gear ratio calc program should be running around 2288 RPM @65mph PERFECT!! campared to a stock military chevy's 3288rpm @65 (th400.4.56 gears and 32" tires stock)
#4
the 2.5 axles are from a 1950's GMC military truck.. they are normal faceload style instead of "toploader" like rockwells.. one wierd fact about them is they are setup passenger side high pinion reverse rotation front, low pinion standard rotation rear using the exact same carriers.. all you have to do up front to be able to run a standard transfer case (instead of the huge heavy military one) is either flip the front around from high pinion to low pinion staying passenger side OR flip axle front to rear and stick the carrier in the spot where cover used to be, making it a driver side low pinion standard rotation.
if you want to keep it passenger side pinion you have to notch the housing for the ring gear and shorten one inner axle shaft, if you flip it over to the driver side you dont have to do either but requires different transfercase (which I already had along with newer 5spd from a IFS equipped chevy)
there are few different ones
10 spline set with 6.67 axle gears (weaker axles)
10 spline set with 7.20 axle gears (weakest axles and VERY RARE 2yrs only I think)
27 spline set with 6.17 axle gears (strongest set)
by comparison the 10 spline axles are about as strong as stock rockwell axles, the 27's are little stronger, but people like rockwells because of the top loader design and there are aftermarket parts for them... onlything available for gm's are stock replacement bearings,seals and a detroit locker
I went with them to try and keep my truck all gm and because they have a better gear ratio for the street unless you are running super tall tires (rockwells come with 6.72 gears)
also drum brakes with 2 wheel cylinders per drum, I am working on a disk setup right now though
here is pic of the inner axle at the splines
if you want to keep it passenger side pinion you have to notch the housing for the ring gear and shorten one inner axle shaft, if you flip it over to the driver side you dont have to do either but requires different transfercase (which I already had along with newer 5spd from a IFS equipped chevy)
there are few different ones
10 spline set with 6.67 axle gears (weaker axles)
10 spline set with 7.20 axle gears (weakest axles and VERY RARE 2yrs only I think)
27 spline set with 6.17 axle gears (strongest set)
by comparison the 10 spline axles are about as strong as stock rockwell axles, the 27's are little stronger, but people like rockwells because of the top loader design and there are aftermarket parts for them... onlything available for gm's are stock replacement bearings,seals and a detroit locker
I went with them to try and keep my truck all gm and because they have a better gear ratio for the street unless you are running super tall tires (rockwells come with 6.72 gears)
also drum brakes with 2 wheel cylinders per drum, I am working on a disk setup right now though
here is pic of the inner axle at the splines
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thanx guys, yeah I would love to have a 400hp cummins in there but thats alot of $$ for something I dont really need.
I also started the project with idea to keep as much of it GM as possible, I had originally tried to source the 8.2L fuel pincher diesel/5spd eaton combo that gm put in buses and dump trucks....but again $$$ for a good running one or $$ to fix a broken one.
Truck is just going to be weekend cruiser for me and GF, might hook it to a sled once or twice for fun.
paint plans are dark blue with icicles hanging down from the body line, interior will probably be either blazer buckets and console up front and stock bench in rear OR 2 dodge ram quad cab benchs with the seat belts in seats.
I also started the project with idea to keep as much of it GM as possible, I had originally tried to source the 8.2L fuel pincher diesel/5spd eaton combo that gm put in buses and dump trucks....but again $$$ for a good running one or $$ to fix a broken one.
Truck is just going to be weekend cruiser for me and GF, might hook it to a sled once or twice for fun.
paint plans are dark blue with icicles hanging down from the body line, interior will probably be either blazer buckets and console up front and stock bench in rear OR 2 dodge ram quad cab benchs with the seat belts in seats.
#10