Big Inch Torque Monsters: Who has them? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Purs · 12-26-2004, 03:38 PM

I'm building a pump gas 496 (I know, it's not that big anymore....) and am going back an forth on whether to drop it into an early A-body GM car (Chevelle, Buick GS, etc) or a '68 SWB that I've got my eye on. Without going into specifics, this engine will be making a conservative 650HP/600TQ. This is NOT a strip only vehicle. It will be 80 percent street driven with an occasional trip to our local 1/8th mile strip. My question is, you guys that have experience with trucks and this level of power, what upgrades are neccessary for safety and reliability. Here are some specific areas I'm concerned with:

1. engine towers/motor mounts
2. driveshaft
3. Rear end (I have a chevelle 12 bolt I'd like to use with Moser axles, etc...)
4. Frame flex/twist under heavy accerlation causing cab/body distortion

Anyone that has experience please share.

Thanks In Advance!

Longhorn Man · 12-26-2004, 03:50 PM

While I don't have all that big an engine, I can answer some of your q's.
1. engine towers/motor mounts
Simple, get stock big block pieces. There are 2 typews, the 68 - 71, and then there are 72. You will pay a butt load either way, the 68 - 71 mounts are expensive, but the frame mounts are dirt cheap. The 72 units are the other way around. Cheap mounts, and expensive on the frame mounts. Personally I'd get the 72 style. Pay once instead of every time you rip a motor mount.

2.driveshaft
Never heard of anyone really havin problems. You could talk to your local drive shaft repair place and see what they can do for you. Being a SWB you can get a one piece shaft with absolutly no problems at all.

3.Rear end (I have a car 12 bolt with Moser axles, etc...)
The car 12 bolt is nothing like the truck 12 bolt. While there are other units out there stronger, i have personally seen a 67 LWB doing 12's in the 1/4 mile with slicks (actually just one slick) and hardly any wheel spin. This was also his daily driver (only vehicle) and he never had any problems.

4. Frame flex/twist under heavy accerlation causing cab/body distortion
Again, i have never personally seen nor heard anything along these lines. There will be some, but being a truck it is kinda made for more abuse than a typical car frame.

Purs · 12-26-2004, 04:14 PM

i've got a buddy with an '86 SWB that's making similar power that has "creases" on the top of the cab because all the twisting involved when he launches at the strip.

Ironically, I've done alot of reading explaining why the truck 12 bolt is mechanically "weaker" than a car 12 bolt... doesn't make sense to me why GM would do that...

1972ChevyGuy · 12-26-2004, 05:18 PM

Talk to Ragenrat... hes got a baddda** BIIIIIIIIIIIIIG block. lol

*rage'nrat638* · 12-26-2004, 08:37 PM

ford 9 " rear end
th400 trans- built to the hilt
638 c.i. dart tall block 850 h.p.

krue · 12-26-2004, 08:48 PM

Now I need a new keyboard, the drool is shorting mine out!

**68 Stepside** · 12-26-2004, 09:05 PM

Yeah, Mark's truck is majorly badassed. I know first-hand, I took a ride in it

He can probably answer most of your questions.

*rage'nrat638* · 12-26-2004, 09:38 PM

Quote:

Originally Posted by 68 Stepside

Yeah, Mark's truck is majorly badassed. I know first-hand, I took a ride in it

He can probably answer most of your questions.

thanks my brother.......

just ordered up 500.00 in goodies for this next summer

got to love those summit gift cards

**68 Stepside** · 12-26-2004, 09:41 PM

Awesome bro!! I haven't done anything to the truck recently, I tried starting it today, but she wouldn't do it

Once I get my surgery done in January, and get back to work in February, I'll be hitting the truck hard. Once I get it driveable, I'm building a garage here...a garage for ME and only ME

Take care bro, hope you had a Merry Christmas.

12-26-2004, 03:38 PM	#1
Purs Got Big Block? Join Date: Apr 2000 Location: West Texas Posts: 1,510	Big Inch Torque Monsters: Who has them? I'm building a pump gas 496 (I know, it's not that big anymore....) and am going back an forth on whether to drop it into an early A-body GM car (Chevelle, Buick GS, etc) or a '68 SWB that I've got my eye on. Without going into specifics, this engine will be making a conservative 650HP/600TQ. This is NOT a strip only vehicle. It will be 80 percent street driven with an occasional trip to our local 1/8th mile strip. My question is, you guys that have experience with trucks and this level of power, what upgrades are neccessary for safety and reliability. Here are some specific areas I'm concerned with: 1. engine towers/motor mounts 2. driveshaft 3. Rear end (I have a chevelle 12 bolt I'd like to use with Moser axles, etc...) 4. Frame flex/twist under heavy accerlation causing cab/body distortion Anyone that has experience please share. Thanks In Advance! __________________ "Experience is what you get when you didn't get what you wanted." Last edited by Purs; 12-26-2004 at 03:42 PM.

12-26-2004, 04:14 PM	#3
Purs Got Big Block? Join Date: Apr 2000 Location: West Texas Posts: 1,510	i've got a buddy with an '86 SWB that's making similar power that has "creases" on the top of the cab because all the twisting involved when he launches at the strip. Ironically, I've done alot of reading explaining why the truck 12 bolt is mechanically "weaker" than a car 12 bolt... doesn't make sense to me why GM would do that... __________________ "Experience is what you get when you didn't get what you wanted."

12-26-2004, 08:48 PM	#6
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Now I need a new keyboard, the drool is shorting mine out! __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

12-26-2004, 09:05 PM	#7
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	Yeah, Mark's truck is majorly badassed. I know first-hand, I took a ride in it He can probably answer most of your questions. __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

12-26-2004, 09:41 PM	#9
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	Awesome bro!! I haven't done anything to the truck recently, I tried starting it today, but she wouldn't do it Once I get my surgery done in January, and get back to work in February, I'll be hitting the truck hard. Once I get it driveable, I'm building a garage here...a garage for ME and only ME Take care bro, hope you had a Merry Christmas. __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

12-26-2004, 03:50 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	While I don't have all that big an engine, I can answer some of your q's. 1. engine towers/motor mounts Simple, get stock big block pieces. There are 2 typews, the 68 - 71, and then there are 72. You will pay a butt load either way, the 68 - 71 mounts are expensive, but the frame mounts are dirt cheap. The 72 units are the other way around. Cheap mounts, and expensive on the frame mounts. Personally I'd get the 72 style. Pay once instead of every time you rip a motor mount. 2.driveshaft Never heard of anyone really havin problems. You could talk to your local drive shaft repair place and see what they can do for you. Being a SWB you can get a one piece shaft with absolutly no problems at all. 3.Rear end (I have a car 12 bolt with Moser axles, etc...) The car 12 bolt is nothing like the truck 12 bolt. While there are other units out there stronger, i have personally seen a 67 LWB doing 12's in the 1/4 mile with slicks (actually just one slick) and hardly any wheel spin. This was also his daily driver (only vehicle) and he never had any problems. 4. Frame flex/twist under heavy accerlation causing cab/body distortion Again, i have never personally seen nor heard anything along these lines. There will be some, but being a truck it is kinda made for more abuse than a typical car frame.

12-26-2004, 05:18 PM	#4
1972ChevyGuy Registered User Join Date: Nov 2002 Location: Kannapolis, NC Posts: 552	Talk to Ragenrat... hes got a baddda** BIIIIIIIIIIIIIG block. lol

12-26-2004, 08:37 PM	#5
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	ford 9 " rear end th400 trans- built to the hilt 638 c.i. dart tall block 850 h.p.



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