Should I cut the frame??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BaroneDog · 01-03-2018, 09:38 PM

Doing a test fit on my 67 LQ conversion. Headers (Thorley 323Y) are almost touching on the passenger side and significantly interfering with the frame on the drivers side. Reading around a bit, it looks like the 1967 year frame rails are a bit wider than later years. It looks like I will need to trim them back a bit to get enough clearance, but figured it would be worth asking the community to see if anyone else ran into this and if they went a different direction.

Moving the engine back or up will not fix it. I have the motor about as far back as it will go. Cannot move more than about another 0.5" before the header will hit the firewall on the pass side. Also, I tried moving the engine up (as if shimming or using a DD slider which is a bit taller) but that did not provide enough clearance either. Other thoughts?

First photo below is pass side with header mounted (but no gasket) and the bottom two are drivers side but the header could not even be fully seated on the head due to frame interference. Ignore the blue tape (just trying to prevent scratches on the shiny new headers!).

Also, for anyone who has the 323Y headers, what type of spark plug wires did you use? Looks like a tight fit.

Many Thanks!

**mongocanfly** · 01-03-2018, 10:47 PM

notching for clearance is pretty common with these swaps...but I was thinking the DT's cleared on those trucks...from the looks of it I would reroute those brake lines as well....

ls1nova71 · 01-03-2018, 11:19 PM

I'd trim the frame up a bit and never look back! Also as Mongo said, probably move those brake lines. I used factory plug wires on my truck, they didn't fit bad at all.

BaroneDog · 01-06-2018, 02:12 PM

Thanks Mongo and LS1. Just finished cutting a notch. Was quicker than I thought. Brake lines also out of the way now. Just need to re-route them. Did you guys go power or stay manual for your brakes?

**mongocanfly** · 01-06-2018, 02:25 PM

mine has hydroboost...

**GMC-YA68** · 01-08-2018, 05:46 PM

I had to shave a tad off for mine Tri-Ys to clear as well. As far as I can remember I used stock plug wires that were on my motor.

**Clyde65** · 01-08-2018, 07:55 PM

I think I had to do 3/4” off both sides( so the match)

01-03-2018, 09:38 PM	#1
BaroneDog Registered User Join Date: Dec 2016 Location: Lexington, MA Posts: 92	Should I cut the frame??? Doing a test fit on my 67 LQ conversion. Headers (Thorley 323Y) are almost touching on the passenger side and significantly interfering with the frame on the drivers side. Reading around a bit, it looks like the 1967 year frame rails are a bit wider than later years. It looks like I will need to trim them back a bit to get enough clearance, but figured it would be worth asking the community to see if anyone else ran into this and if they went a different direction. Moving the engine back or up will not fix it. I have the motor about as far back as it will go. Cannot move more than about another 0.5" before the header will hit the firewall on the pass side. Also, I tried moving the engine up (as if shimming or using a DD slider which is a bit taller) but that did not provide enough clearance either. Other thoughts? First photo below is pass side with header mounted (but no gasket) and the bottom two are drivers side but the header could not even be fully seated on the head due to frame interference. Ignore the blue tape (just trying to prevent scratches on the shiny new headers!). Also, for anyone who has the 323Y headers, what type of spark plug wires did you use? Looks like a tight fit. Many Thanks! Attached Images

01-03-2018, 10:47 PM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,670	Re: Should I cut the frame??? notching for clearance is pretty common with these swaps...but I was thinking the DT's cleared on those trucks...from the looks of it I would reroute those brake lines as well.... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

01-03-2018, 11:19 PM	#3
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: Should I cut the frame??? I'd trim the frame up a bit and never look back! Also as Mongo said, probably move those brake lines. I used factory plug wires on my truck, they didn't fit bad at all. __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

01-06-2018, 02:12 PM	#4
BaroneDog Registered User Join Date: Dec 2016 Location: Lexington, MA Posts: 92	Re: Should I cut the frame??? Thanks Mongo and LS1. Just finished cutting a notch. Was quicker than I thought. Brake lines also out of the way now. Just need to re-route them. Did you guys go power or stay manual for your brakes?

01-06-2018, 02:25 PM	#5
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,670	Re: Should I cut the frame??? mine has hydroboost... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

01-08-2018, 05:46 PM	#6
GMC-YA68 Senior Member Join Date: Mar 2004 Location: Lee's Summit, MO (KC) Posts: 742	Re: Should I cut the frame??? I had to shave a tad off for mine Tri-Ys to clear as well. As far as I can remember I used stock plug wires that were on my motor. __________________ -Keegan- '72 Jimmy 4x4 - 5.3/4L65E/NP205 swap http://67-72chevytrucks.com/vboard/s...d.php?t=663780

01-08-2018, 07:55 PM	#7
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,546	Re: Should I cut the frame??? I think I had to do 3/4” off both sides( so the match) __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.