Crossmember probem, on six to eight conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dcwoodinv · 08-27-2005, 09:06 PM

Hi all New to the board and love all the great informantion. I am putting a 350/350 in my 72 stepside which was stock with a six. I have my 350 back from the shop and is ready to go in. I pulled the six out today and noticed the tranny crossmember is riveted to the fram and is alot further foward than the one for the auto im putting in. I also noticed the motor mount brackets are further back than the 350. Are these the only differances I will find and how much trouble is it to modify?

Thanks Doug

krue · 08-27-2005, 09:11 PM

You need a crossmember for the auto, it bolts in. I hear getting the manual xmember is a pain to get out. The engine mounts are different from the sixes to the eights, but some people opt to mount the sbc in the six position to move the weight to the rear a little.

*Randy70C-10* · 08-27-2005, 09:16 PM

I have my 350 in the 6 position, I always thought that they look like they are too far forward in the V-8 position.

dcwoodinv · 08-27-2005, 09:35 PM

Thats what I was afraid of, looks like I will be doing allot of grinding tonight. I have the crossmember from the parts truck as well as the V8 motor mount brckets but since I will have to have a driveline built I may just set it in the six position.

Doug

shifty · 08-27-2005, 11:24 PM

can someone tell me what the hell those little rounded things are and how to most easily remove them? i noticed the exhaust bungs, xmembers and everything else on my frame is installed with those things. what kind of hardware is recommended to put in the place of those things?

dcwoodinv · 08-27-2005, 11:40 PM

The look like steel rivits to me, I am going to just drind them off.

kelsfine69 · 08-28-2005, 01:01 AM

Drill a hole thru them as big as you can without wrecking the metal frame hole then take a air hammer and knock the head off, then punch the rivet out. Buy the time you get the last one out you wil be a expert

If you put the proper engine mount in and the trans mount in the proper holes then you dont have to custom build a driveshaft, any wrecker will do.

dcwoodinv · 08-28-2005, 01:12 AM

Thanks for all the help...Anybody have a driveshaft for a shortbed stepside with a TH350?

Green Machine · 08-28-2005, 02:23 AM

Took me about 1/2 hour per rivot to grind them off on my V8 swap. I put it in the forward position, but I have a clutch linkage and floor shift to properly locate.

*FormerMember* · 08-28-2005, 10:15 AM

took me about 20 mins a side.

shifty · 08-28-2005, 02:17 PM

i have no use for my driveshaft right now, but i dunno if it will fit. i'm going to try and have my current driveshaft shortened. it's from an inline 6 + 3spd.

dcwoodinv · 08-28-2005, 04:07 PM

Shifty if it is off a V8 with a 350 auto I would be intrested in it. How much do you want shipping to 87144, Rio Rancho New Mexico.

Doug

shifty · 08-28-2005, 06:14 PM

It's off a 6cyl.

55chevy · 08-28-2005, 07:55 PM

This should be a FAQ, or maybe there is one on converting a 6 cyl to a V8?

**guyryan100** · 08-28-2005, 08:56 PM

If you put motor in the forward (v8) position, you will need different engine towers. The I6 towers will work on your V8 only in the I6 position.

dcwoodinv · 08-28-2005, 09:57 PM

I have both sets of towers it's just a matter of preference I suppose. I f I can find a stock driveline I will move it foward if not then I will keep it to the rear since I will have to have a driveline built anyway.

Cheesewagon · 08-29-2005, 01:21 AM

dcwoodinv I sent you a PM on a driveshaft. Latter Tom

dcwoodinv · 08-29-2005, 08:03 AM

ttt

68Stepbed · 08-29-2005, 01:45 PM

My driveshaft fit right in with all the V8 mounts and a long tail shaft TH350. It wouldn't have fit with a short tail shaft tranny.

Joe67 · 08-29-2005, 01:49 PM

I plan to run a V8 in my 1972 chassis. I saved the auto trans crossmember from my '67 chassis (6 cyl / 2 speed powerglide).

Can I use this crossmember in my '72 chassis with either a BBC or SBC & a 350 auto trans?

dcwoodinv · 08-29-2005, 09:59 PM

"Quote' My driveshaft fit right in with all the V8 mounts and a long tail shaft TH350. It wouldn't have fit with a short tail shaft tranny.

68STEPBED,

Did your six have a standard or a auto tranny. And if it was an auto did you use the foward or rear mounting position?

Doug

08-27-2005, 09:06 PM	#1
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	Crossmember probem, on six to eight conversion Hi all New to the board and love all the great informantion. I am putting a 350/350 in my 72 stepside which was stock with a six. I have my 350 back from the shop and is ready to go in. I pulled the six out today and noticed the tranny crossmember is riveted to the fram and is alot further foward than the one for the auto im putting in. I also noticed the motor mount brackets are further back than the 350. Are these the only differances I will find and how much trouble is it to modify? Thanks Doug

08-27-2005, 09:11 PM	#2
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	You need a crossmember for the auto, it bolts in. I hear getting the manual xmember is a pain to get out. The engine mounts are different from the sixes to the eights, but some people opt to mount the sbc in the six position to move the weight to the rear a little. __________________ "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"

08-27-2005, 11:24 PM	#5
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	can someone tell me what the hell those little rounded things are and how to most easily remove them? i noticed the exhaust bungs, xmembers and everything else on my frame is installed with those things. what kind of hardware is recommended to put in the place of those things? __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

08-28-2005, 02:23 AM	#9
Green Machine Senior Member Join Date: Jul 2004 Location: Estherville, Iowa Posts: 3,371	Took me about 1/2 hour per rivot to grind them off on my V8 swap. I put it in the forward position, but I have a clutch linkage and floor shift to properly locate. __________________ 1968 C10 307 3spd Long Fleet ------ http://67-72chevytrucks.com/vboard/s...d.php?t=201103 1970 C10 305 Super T10 Long Fleet --- http://67-72chevytrucks.com/vboard/s...d.php?t=202285 1971 C20 383 TH350 Dana Posi ----- http://67-72chevytrucks.com/vboard/s...d.php?t=206894 2001 GMC Sierra 1500 C3 6.0

08-28-2005, 02:17 PM	#11
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	i have no use for my driveshaft right now, but i dunno if it will fit. i'm going to try and have my current driveshaft shortened. it's from an inline 6 + 3spd. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

08-27-2005, 09:16 PM	#3
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	I have my 350 in the 6 position, I always thought that they look like they are too far forward in the V-8 position.

08-27-2005, 09:35 PM	#4
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	Thats what I was afraid of, looks like I will be doing allot of grinding tonight. I have the crossmember from the parts truck as well as the V8 motor mount brckets but since I will have to have a driveline built I may just set it in the six position. Doug

08-27-2005, 11:40 PM	#6
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	The look like steel rivits to me, I am going to just drind them off.

08-28-2005, 01:01 AM	#7
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Drill a hole thru them as big as you can without wrecking the metal frame hole then take a air hammer and knock the head off, then punch the rivet out. Buy the time you get the last one out you wil be a expert If you put the proper engine mount in and the trans mount in the proper holes then you dont have to custom build a driveshaft, any wrecker will do.

08-28-2005, 01:12 AM	#8
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	Thanks for all the help...Anybody have a driveshaft for a shortbed stepside with a TH350?

08-28-2005, 10:15 AM	#10
FormerMember Account Suspended Join Date: Feb 2004 Posts: 3,051	took me about 20 mins a side.

08-28-2005, 04:07 PM	#12
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	Shifty if it is off a V8 with a 350 auto I would be intrested in it. How much do you want shipping to 87144, Rio Rancho New Mexico. Doug

08-28-2005, 06:14 PM	#13
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,373	It's off a 6cyl. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

08-28-2005, 07:55 PM	#14
55chevy Car Truck Bike Nut Join Date: Aug 2005 Location: Suffolk Virginia Posts: 850	Faq This should be a FAQ, or maybe there is one on converting a 6 cyl to a V8? __________________ Snow free Florida panhandle, don't miss Indiana winters Temp in Suffolk Virginia, Sentenced 2 to 5 years LOL 68 shortfleet project 94 3500 TD dually so many cars so little time 72 K2 CST 2WD Blazer

08-28-2005, 08:56 PM	#15
guyryan100 Registered User Join Date: Sep 2001 Location: Cumming, GA Posts: 483	If you put motor in the forward (v8) position, you will need different engine towers. The I6 towers will work on your V8 only in the I6 position.



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08-28-2005, 09:57 PM	#16
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	I have both sets of towers it's just a matter of preference I suppose. I f I can find a stock driveline I will move it foward if not then I will keep it to the rear since I will have to have a driveline built anyway.

08-29-2005, 01:21 AM	#17
Cheesewagon Senior Member Join Date: Jan 2002 Location: Perrysburg, Ohio, USA Posts: 409	dcwoodinv I sent you a PM on a driveshaft. Latter Tom __________________ '91 suburban 350 TBI - R 700 4 new daily driver '72 Cheyenne Super 49,000miles 350/350 frame up resto w/ matching numbers.

08-29-2005, 08:03 AM	#18
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	ttt

08-29-2005, 01:45 PM	#19
68Stepbed Registered User Join Date: Mar 2005 Location: 10-Uh-See Posts: 5,609	My driveshaft fit right in with all the V8 mounts and a long tail shaft TH350. It wouldn't have fit with a short tail shaft tranny. __________________ Matt 68 C10 stepside, LS1/700R4, TCI Engineering suspension system

08-29-2005, 01:49 PM	#20
Joe67 67 is sold Join Date: Apr 2001 Location: Troy, Michigan Posts: 6,733	I plan to run a V8 in my 1972 chassis. I saved the auto trans crossmember from my '67 chassis (6 cyl / 2 speed powerglide). Can I use this crossmember in my '72 chassis with either a BBC or SBC & a 350 auto trans? __________________ Joe - Formerly 67c10step ------------------------------- 1967 Chevy Stepside - ECE 4/6, fuelcell, 5lug - SOLD gr8lakes - My ebay auctions Click here to order forum apparel :: Click here to become a subscribing member Last edited by Joe67; 08-30-2005 at 07:10 AM.

08-29-2005, 09:59 PM	#21
dcwoodinv Registered User Join Date: Jul 2005 Location: Rio Rancho,New Mexico Posts: 20	"Quote' My driveshaft fit right in with all the V8 mounts and a long tail shaft TH350. It wouldn't have fit with a short tail shaft tranny. 68STEPBED, Did your six have a standard or a auto tranny. And if it was an auto did you use the foward or rear mounting position? Doug

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