Floor differences - The 1947 - Present Chevrolet & GMC Truck Message Board Network

redsled87 · 02-19-2015, 01:09 PM

Is there a difference between a 74 and an 87 2wd automatic floor pan?

Chaplain · 02-19-2015, 01:23 PM

I want to say yes. Some trans require a bigger tunnel. I'll wait with you to see what the veterans have to say...

enaberif · 02-19-2015, 01:24 PM

Quote:

Originally Posted by Chaplain

I want to say yes. Some trans require a bigger tunnel. I'll wait with you to see what the veterans have to say...

Larger tunnel existed on the 4wds or the manual trucks because of the transfer case and transmission.

El Dorado Jim · 02-21-2015, 10:05 PM

Quote:

Originally Posted by enaberif

Larger tunnel existed on the 4wds or the manual trucks because of the transfer case and transmission.

2 wheel drives that ran the 400 turbo trans. had the larger floor pan like the 4 wheel drives and the manual trans in the 70's

Chaplain · 02-23-2015, 02:14 AM

Does anyone have pics to demonstrate the difference?

ray_mcavoy · 02-23-2015, 12:30 PM

Here are some pictures that show the differences --> http://forum.73-87chevytrucks.com/sm...?topic=11838.0

It looks like there were a number of different styles used over the years.

2wd low hump -- The early ones (73-80) have the hump stopping near the front edge of the seat. See pics #1 & #5 in the above link. While the later ones (81+) have the hump extending back under the seat a little bit. See pic #6 in the above link.

2wd high hump -- The early ones look like they use the same basic floor pan stamping as the low hump except the trans tunnel has been punched/cut out and fitted with a higher bolt-in hump. See pic #3. I'm not sure what year they changed, but the later ones have a high hump that's an integral part of the floor. See pic #7.

4wd high hump -- All 4x4's have a high hump that extends back under the seat for transfer case clearance. The early years have a bolt-in front section and a spot-welded-in rear section. This style is shown in pics #4 and #11 but the seats are blocking the view of the transfer case portion of the hump. A good pic of that can be seen here --> http://67-72chevytrucks.com/vboard/s...59&postcount=7

The later year 4x4's have a high hump that's an integral part of the floor See pic #8 & #10 in the earlier link.

02-19-2015, 01:23 PM	#2
Chaplain Registered User Join Date: Oct 2014 Location: TN Posts: 294	Re: Floor differences I want to say yes. Some trans require a bigger tunnel. I'll wait with you to see what the veterans have to say...

02-19-2015, 01:09 PM	#1
redsled87 Registered User Join Date: Dec 2011 Location: Lanc Co PA Posts: 226	Floor differences Is there a difference between a 74 and an 87 2wd automatic floor pan? __________________ 1987 R10 Pump Gas 496/TH375 Best 1/4 pass to date 60' 1.49 1/4 10.93 MPH 120

02-23-2015, 02:14 AM	#5
Chaplain Registered User Join Date: Oct 2014 Location: TN Posts: 294	Re: Floor differences Does anyone have pics to demonstrate the difference?

02-23-2015, 12:30 PM	#6
ray_mcavoy Registered User Join Date: Nov 2009 Location: Sherman, ME Posts: 2,359	Re: Floor differences Here are some pictures that show the differences --> http://forum.73-87chevytrucks.com/sm...?topic=11838.0 It looks like there were a number of different styles used over the years. 2wd low hump -- The early ones (73-80) have the hump stopping near the front edge of the seat. See pics #1 & #5 in the above link. While the later ones (81+) have the hump extending back under the seat a little bit. See pic #6 in the above link. 2wd high hump -- The early ones look like they use the same basic floor pan stamping as the low hump except the trans tunnel has been punched/cut out and fitted with a higher bolt-in hump. See pic #3. I'm not sure what year they changed, but the later ones have a high hump that's an integral part of the floor. See pic #7. 4wd high hump -- All 4x4's have a high hump that extends back under the seat for transfer case clearance. The early years have a bolt-in front section and a spot-welded-in rear section. This style is shown in pics #4 and #11 but the seats are blocking the view of the transfer case portion of the hump. A good pic of that can be seen here --> http://67-72chevytrucks.com/vboard/s...59&postcount=7 The later year 4x4's have a high hump that's an integral part of the floor See pic #8 & #10 in the earlier link.



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