Help with front crossmember fasteners - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68C10 · 10-24-2003, 09:19 PM

I'm installing a '72 disc brake front crossmember on my '68. There are 5 - 1/2" bolts on each side. 3 that go through the bottom flange of the frame and 2 that go through the side of the frame. The two that go through the side (near the top) are VERY tight. They seem to be threading into the side of the frame as I tighten them ... is that right? I did POR15 it so the holes are snug but they seem way too tight.
My other question is about the 2 - 3/8 bolts (per side) that pass through the frame and thread into captive nuts on the crossmember. The two in the rear bolt up great but the frame holes on the front ones don't line up quite right. Has anyone had this problem and what did you do about it? I would just enlarge the holes in the frame but I don't want to through the alignment off. I hope I explained my problem so someone can understand it.
All observations and suggestions gratefully accepted.

phantom dually · 10-25-2003, 10:18 AM

Do you have pics. If it is a non threaded hole use a circular file and file the por away. If it is a threaded hole then use a thread chaser to clean the hole out. You will not be able to properly get a torque reading if the por is still in these areas when tightening

68C10 · 10-25-2003, 11:04 AM

OK I got the 1/2 holes taken care of but I still can't get the 3/8" to line up. Any suggestions.
I know lots of guys have put later model crossmembers on early trucks.

phantom dually · 10-25-2003, 02:28 PM

I have heard that when switching crossmembers that a few of the bolt hole may be off a little. As long as the three bolts that mount the member to the frame from the bottom are in and secure you will have to drill the others out to make them work.

Tx Firefighter · 10-25-2003, 02:34 PM

There is 1 bolt per side that doesn't exactly line up. You need to "adjust" the hole sideways slightly to get the bolt in. As long as all of the other bolts are snug, you don't have any worry about screwing up the alignment.

I'm ashamed to say, but I've actually left those two bolts completely out, when doing this job.

68C10 · 10-25-2003, 05:15 PM

Thanks guys.
I ended up "releaving" the holes in the frame just enough to get the bolts in place. It worked great and its all in there solid as a rock.:p

phantom dually · 10-26-2003, 12:57 PM

OK then!

10-24-2003, 09:19 PM	#1
68C10 Registered User Join Date: Dec 1999 Location: Central New Jersey, USA Posts: 328	Help with front crossmember fasteners I'm installing a '72 disc brake front crossmember on my '68. There are 5 - 1/2" bolts on each side. 3 that go through the bottom flange of the frame and 2 that go through the side of the frame. The two that go through the side (near the top) are VERY tight. They seem to be threading into the side of the frame as I tighten them ... is that right? I did POR15 it so the holes are snug but they seem way too tight. My other question is about the 2 - 3/8 bolts (per side) that pass through the frame and thread into captive nuts on the crossmember. The two in the rear bolt up great but the frame holes on the front ones don't line up quite right. Has anyone had this problem and what did you do about it? I would just enlarge the holes in the frame but I don't want to through the alignment off. I hope I explained my problem so someone can understand it. All observations and suggestions gratefully accepted. __________________ 68C10 1968 C10 SWB No Options but 40K original miles 1967 K20 LWB 283 4-speed South Plainfield, NJ

10-25-2003, 10:18 AM	#2
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,792	Do you have pics. If it is a non threaded hole use a circular file and file the por away. If it is a threaded hole then use a thread chaser to clean the hole out. You will not be able to properly get a torque reading if the por is still in these areas when tightening __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448

10-25-2003, 11:04 AM	#3
68C10 Registered User Join Date: Dec 1999 Location: Central New Jersey, USA Posts: 328	OK I got the 1/2 holes taken care of but I still can't get the 3/8" to line up. Any suggestions. I know lots of guys have put later model crossmembers on early trucks. __________________ 68C10 1968 C10 SWB No Options but 40K original miles 1967 K20 LWB 283 4-speed South Plainfield, NJ

10-25-2003, 02:28 PM	#4
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,792	I have heard that when switching crossmembers that a few of the bolt hole may be off a little. As long as the three bolts that mount the member to the frame from the bottom are in and secure you will have to drill the others out to make them work. __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448

10-25-2003, 02:34 PM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	There is 1 bolt per side that doesn't exactly line up. You need to "adjust" the hole sideways slightly to get the bolt in. As long as all of the other bolts are snug, you don't have any worry about screwing up the alignment. I'm ashamed to say, but I've actually left those two bolts completely out, when doing this job. __________________ I'm on the Instagram- @Gearhead_Kevin

10-25-2003, 05:15 PM	#6
68C10 Registered User Join Date: Dec 1999 Location: Central New Jersey, USA Posts: 328	Thanks guys. I ended up "releaving" the holes in the frame just enough to get the bolts in place. It worked great and its all in there solid as a rock.:p __________________ 68C10 1968 C10 SWB No Options but 40K original miles 1967 K20 LWB 283 4-speed South Plainfield, NJ

10-26-2003, 12:57 PM	#7
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,792	OK then! __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448



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