Do you have to narrow the stock rearend for the 20x15 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Racie · 06-21-2010, 09:08 PM

Does anyone know the backspace required to run the stock rear end on the 68' fleetside to run the 20x15's? I will be doing the tub mod to the bed but I was hoping to not have to narrow the rearend. Anyone know the answer?

1968SWBBigBlock · 06-21-2010, 10:39 PM

I assume you are lookig at 20" tall x 15: wide?
I have 8.75 negitive offset to fit my 18.5" wide Hoosiers radials
No the rearend is not narrowed - you do have to use non tapered springs, relocate or move the ebrake cable out of the way and cut the bed back flush with the frame and make a larger tub

chevyblazer · 06-22-2010, 12:16 AM

depends on how wide they are from center outsides

petey-pablo · 06-22-2010, 05:49 AM

Quote:

Originally Posted by 1968SWBBigBlock

I assume you are lookig at 20" tall x 15: wide?
I have 8.75 negitive offset to fit my 18.5" wide Hoosiers radials
No the rearend is not narrowed - you do have to use non tapered springs, relocate or move the ebrake cable out of the way and cut the bed back flush with the frame and make a larger tub

Do you hav any pictures from the back of those Hoosiers mounted I'd like to see what the look like on our trucks.

Racie · 06-22-2010, 07:00 AM

Quote:

Originally Posted by chevyblazer

depends on how wide they are from center outsides

I will be ordering the wheels so I will have them made to fit. I really don't want to narrow the rear just to do it. If I have to get into narrowing the rear end I may just stick with a 20x10 and run 295/40/20 tires.

Racie · 06-22-2010, 07:02 AM

Quote:

Originally Posted by 1968SWBBigBlock

I assume you are lookig at 20" tall x 15: wide?
I have 8.75 negitive offset to fit my 18.5" wide Hoosiers radials
No the rearend is not narrowed - you do have to use non tapered springs, relocate or move the ebrake cable out of the way and cut the bed back flush with the frame and make a larger tub

Thanks and yes I do mean 20" tall plan on ordering Billets for the truck and I will be having them built. Thanks for the good info...

1968SWBBigBlock · 06-22-2010, 07:23 PM

Attached will be some photos from behind -I dropped the rearend a couple of more inchs since I took this photo

Racie · 06-22-2010, 09:36 PM

Quote:

Originally Posted by 1968SWBBigBlock

Attached will be some photos from behind -I dropped the rearend a couple of more inchs since I took this photo

Absolutely bad ass! Beautiful truck...Thanks for all the info and help!

petey-pablo · 06-23-2010, 02:48 AM

Quote:

Originally Posted by 1968SWBBigBlock

Attached will be some photos from behind -I dropped the rearend a couple of more inchs since I took this photo

Nice looks good all rubber from the back any pictures of the inside of the bed? I am looking to do something like this to my truck as well but don't want to have to narrow the rearend, and yours just looks bad ass. I have some pictures of another board members truck that did the same just cut the bed and widden the wheel wells. I have to find it and start doing the research to get this project on the way.. Thanks

Hottrucks · 06-23-2010, 08:15 AM

I did mine cut the bed and the wheel tub about an inch in the rebolted the tub in.I added 5" to the tub..my stock ralleys have 4" of back space added to them and I have 31x15.5x15's

1968SWBBigBlock · 06-23-2010, 08:46 AM

Sorry I do not have any pictures of the bed - at least not worth looking at.
From inside the bed it looks totaly stock, Hottrucks shot some great photos for your consideration.

Hottrucks · 06-23-2010, 09:29 AM

heres one of the bed not great but you get the idea..I painted the inside of the bed with semi rustolium black to clean it up..but keep in mind my bed gets used pretty hard as you can see this is what it does on the weekends .... LOL ....

Hottrucks · 06-23-2010, 09:54 AM

on a side note if your tires are more that 29" tall and you have a c notch the tires are going to hit the top of the tub...my truck was built for 29" tire but since I got a deal on a set of 31x15.5's and now 31x16.5 wrinkle walls I can't dump to the bottom of the notch..I have no idea how close it is because I can get my fat head under to see...lol

I would also like ot find a early rear axle I think the extra 1/2" narrower on each side would help sidewall to bed clearance...its REALLY cose now and does rub on occation..another issue that would be resovled by going back to the 29's

petey-pablo · 06-23-2010, 11:34 AM

Quote:

Originally Posted by Hottrucks

I did mine cut the bed and the wheel tub about an inch in the rebolted the tub in.I added 5" to the tub..my stock ralleys have 4" of back space added to them and I have 31x15.5x15's

Thanks This mod looks very easy to do on Metal, beds what about a wooden bed ? Would it be the same or would I or anyone else run into problems on a wooden bed I want to do this to my 72.
Sorry Racie didn't mean to jack your thread.

Racie · 06-23-2010, 11:44 AM

Quote:

Originally Posted by petey-pablo

Thanks This mod looks very easy to do on Metal, beds what about a wooden bed ? Would it be the same or would I or anyone else run into problems on a wooden bed I want to do this to my 72.
Sorry Racie didn't mean to jack your thread.

No problem bro! Just trying to pick up as much as I can so I won't be fixing mistakes they can be costly.

Hottrucks · 06-23-2010, 11:46 AM

Aren't the wheel tubs the same?? If I had the availablity I would have used another tub to make the patch to widen it.It would have kept that ridge in the tub to make it look more stock

petey-pablo · 06-23-2010, 06:56 PM

Quote:

Originally Posted by Hottrucks

Aren't the wheel tubs the same?? If I had the availablity I would have used another tub to make the patch to widen it.It would have kept that ridge in the tub to make it look more stock

Yes wheel tubs are the same but dont you guys cut the bed alittle too I would asume the wood bed is made differently around that area. Metal bed has more support I would think

maybe i'm wrong.

Hottrucks · 06-23-2010, 07:15 PM

yea I had to cut about 3" out...and there one support mid wheel that had to be cut.. heres a pic of the bottom of my bed before the work also notice the line..that what needed to be cut out

06-21-2010, 09:08 PM	#1
Racie Registered User Join Date: Sep 2008 Location: Dallas,TX Posts: 328	Do you have to narrow the stock rearend for the 20x15 Does anyone know the backspace required to run the stock rear end on the 68' fleetside to run the 20x15's? I will be doing the tub mod to the bed but I was hoping to not have to narrow the rearend. Anyone know the answer?

06-21-2010, 10:39 PM	#2
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Do you have to narrow the stock rearend for the 20x15 I assume you are lookig at 20" tall x 15: wide? I have 8.75 negitive offset to fit my 18.5" wide Hoosiers radials No the rearend is not narrowed - you do have to use non tapered springs, relocate or move the ebrake cable out of the way and cut the bed back flush with the frame and make a larger tub __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

06-22-2010, 12:16 AM	#3
chevyblazer Registered User Join Date: May 2010 Location: tijuana b.c. Posts: 221	Re: Do you have to narrow the stock rearend for the 20x15 depends on how wide they are from center outsides __________________ cucharitas customs

06-22-2010, 07:23 PM	#7
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Do you have to narrow the stock rearend for the 20x15 Attached will be some photos from behind -I dropped the rearend a couple of more inchs since I took this photo Attached Images __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

06-23-2010, 08:15 AM	#10
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Do you have to narrow the stock rearend for the 20x15 I did mine cut the bed and the wheel tub about an inch in the rebolted the tub in.I added 5" to the tub..my stock ralleys have 4" of back space added to them and I have 31x15.5x15's Attached Images __________________ 1970 C10 CST fleetside 472 ....big dreams little cash... http://67-72chevytrucks.com/vboard/s...d.php?t=335721 SunShine Syndicate.. Mikes Sandwich Fair Run OCT 8th 2011 http://www.thesandwichfair.com/html/...auto_show.html

06-23-2010, 08:46 AM	#11
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Do you have to narrow the stock rearend for the 20x15 Sorry I do not have any pictures of the bed - at least not worth looking at. From inside the bed it looks totaly stock, Hottrucks shot some great photos for your consideration. __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

06-23-2010, 09:29 AM	#12
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Do you have to narrow the stock rearend for the 20x15 heres one of the bed not great but you get the idea..I painted the inside of the bed with semi rustolium black to clean it up..but keep in mind my bed gets used pretty hard as you can see this is what it does on the weekends .... LOL .... Attached Images

06-23-2010, 09:54 AM	#13
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Do you have to narrow the stock rearend for the 20x15 on a side note if your tires are more that 29" tall and you have a c notch the tires are going to hit the top of the tub...my truck was built for 29" tire but since I got a deal on a set of 31x15.5's and now 31x16.5 wrinkle walls I can't dump to the bottom of the notch..I have no idea how close it is because I can get my fat head under to see...lol I would also like ot find a early rear axle I think the extra 1/2" narrower on each side would help sidewall to bed clearance...its REALLY cose now and does rub on occation..another issue that would be resovled by going back to the 29's

06-23-2010, 11:46 AM	#16
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Do you have to narrow the stock rearend for the 20x15 Aren't the wheel tubs the same?? If I had the availablity I would have used another tub to make the patch to widen it.It would have kept that ridge in the tub to make it look more stock __________________ 1970 C10 CST fleetside 472 ....big dreams little cash... http://67-72chevytrucks.com/vboard/s...d.php?t=335721 SunShine Syndicate.. Mikes Sandwich Fair Run OCT 8th 2011 http://www.thesandwichfair.com/html/...auto_show.html

06-23-2010, 07:15 PM	#18
Hottrucks Redefining LowBudget Join Date: Mar 2009 Location: lebanon Cow Hampshire Posts: 4,538	Re: Do you have to narrow the stock rearend for the 20x15 yea I had to cut about 3" out...and there one support mid wheel that had to be cut.. heres a pic of the bottom of my bed before the work also notice the line..that what needed to be cut out Attached Images



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