BBC in 67-72 4x4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Blue_71 · 07-08-2003, 02:51 PM

ive been talking with yukon jack about his swap, and he told me a couple ways he found to do it..
1. body lift and firwall work
or
2. move everythign forward, shorten front shaft and lengthen rear

is there any other ways to do it? i tried to search colorado k5 but it said members only could search and it said you had to pay for membership.... not about to do that. preferbly, i dont want to mess with driveshafts or the firewall, and i dont like body lifts.. another problem is my 31s look like rubber bands already, and i cant afford any bigger so i dont want to go taller at this time

GMC71k20 · 07-08-2003, 02:53 PM

how far do you have to move everything forward? do you have to cut up the floor for the shifters? what about clutch linkage?

Blue_71 · 07-08-2003, 02:56 PM

yukon said from what he found, everything had to go forward 2 inches... 2 inches cause alot of problems IMO (driveshafts, clutch, maybe fan clearance) more then i want to mess with... im guessing the hump would probably have to be cut up for new shifter holes

Quote:

Josh, when I got my big block I did a lot of research to see the different ways people have put them in 67-72 Chevy 4wd's. I generally found two options, move the engine forward about two inches or leave the engine in the small block position and run a body lift or massage the firewall for valve cover clearance. I was already planning a body lift to line my cab up better with my headache rack, so that is the method I did.

**jamie72** · 07-08-2003, 05:08 PM

hey josh may i can help you out,just bring up that bb and i`ll trade you a 406 i got on the stand...
jamie

Truck Hippy · 07-08-2003, 08:03 PM

Hey guys. I put a 454 into a 72' swb 4x4 several years ago and I didn't move anything. Well I really changed the motor 2 times but the first time all I did was put it in. The second time I did mark where the valve covers came close to the firewall and before I put in the second BB, I gave it a little love tap to make sure the motor could move with out hitting. The motor fit, no problems. I even had HEI in it. This is the only 4x4 I have put a BB in.

GMC71k20 · 07-08-2003, 09:19 PM

i wouldnt mind going with an electric fan and my rear driveshaft looks like hell and has a little warp to it so maybe that wouldnt be too bad.

Chevy409 · 07-08-2003, 09:39 PM

A few swings with the hammer against the firewall and she'll slide right in there...

Class of 69 · 07-08-2003, 09:51 PM

I'm assuming it's the right valve cover that is too close?? Any pics to show the correct location of the needed love taps? I just acquired a 396 to "drop" in my 69 4x4, so all help with install tips will be appreciated. I like what Truck Hippy said about it fitting right in!! That is what I was "planning " on.

**too much stuff** · 07-09-2003, 12:15 AM

I found that corvette valve covers with the notch in the rear helped. Mine sits in the back holes with a stock hei. It is tight, but it will go. Class of 69, if you are around grand rapids and want to check my 70 with a B.B. , let me know. Been there, done that.

Blue_71 · 07-09-2003, 12:21 AM

too much stuff--- any pics of those covers?

sakohntr · 07-09-2003, 12:22 AM

I put a Big Block in my shortbox that was originally a smallblock with very few problems. I did move it forward almost 2 inches so i would not have to bash in the firewall. The front driveshaft worked out alright but i also lifted it 6 inches. I am also using a 4 core radiator and a longwater pump setup, so dont be fooled by fan clearance. It was a manual shift truck so i also slid the shift pivot up. The floor hump was also cut with new holes to accomodate the relocation. You can get a cover from a big block, AT, 2 wd (there will be no existing holes) and just cut your new ones in it. The HEI fits great now and the valve covers do not hit either. Now the truck is as it should have been from the factory!!

casey · 07-09-2003, 12:52 AM

excuse my ignorance but didn't the 4x4s come with a big block?, why all the customizing to fit a BB in a 4x4 unless they never came with one

Blue_71 · 07-09-2003, 12:59 AM

67-72 4x4s never came from the factory as big block, 1 ton, dually, or longhorn

**too much stuff** · 07-12-2003, 03:37 PM

blue 71, no pics available, but drivers side rear lower corner is layed back to accomodate the power brake booster in a corvette (so i am told) You will know it if you see it.

Class of 69 · 07-12-2003, 04:02 PM

casey, my ignorance too!!

I didn't know they were not a factory option until the chassis was loaded on the trailer and they all said " have fun getting that in there"

too much stuff, I know the cover you speak of.....is it the left side that has the clearance problem??

Truck Hippy · 07-12-2003, 06:54 PM

This is kinda long but its what all I ran into putting a 454 into a 72' swb 4x4 with a/c. First the motor. It was a some what stock 454 with a 69' 396/325 cast iron intake and the correct truck exhaust manifolds, stock valve covers, ect. I was trying to make the truck "look" factory, hince no chrome, correct brackets, everything except the HEI. The install was pretty straight foward but i suggest doing a few things first. On a 71-72 truck with cable gas pedel, there are 3 small bolts (see photo) that hold the gas pedel to the fire wall, these need to be made shorter. My valve cover didn't hit the fire wall, it hit one of these bolts. Next I had to grind off a small "nub" on the lower front drivers side manifold because it hit the frame in front of the motor mount. This took all of 2 minutes. Now my truck was an automatic so I tried to use a longer dipstick for the trans but it didn't work out very well so I just used to stock short one. I recomend removing the drivers side valve cover when putting in the motor. It will rub the power brake booster as it goes by. If you don't have A/C, it may go by ok. I don't have any pictures of the truck with a BB and I don't remember where to put the "love taps" but you may be able to look at a 2wb bb truck and kinda get an idea. Now these were "love taps", I didn't total loss my fire wall at all. I used a hammer with a ball end on it and a smaller hammer to hit it with. I put the ball on the fire wall and gave it a few taps. On my truck, I didn't HAVE to put them but the motor is very close and I thought it would be alot easer in the long run. I didn't move the motor foward, the truck had no body lift, I used the stock gas pedel cable. I put the motor in complete except carb, dis. cap, and brackets. Now I raised h*ll in this truck. That 454 would light up my 33x12.50's and it was a blast to drive. If I remember right this is all I had to do. I even changed the cam out with the motor still in the truck. If anybody has any questions, drop me a line at:
wesbaird@charter.net I'll be happy to help out if I can. Would I do it again? You dam right!

Truck Hippy · 07-12-2003, 06:57 PM

sorry about the picture, either me or my camera can't take a good close up picture.

midyearvet@aol. · 07-12-2003, 07:20 PM

I have a 427 in my 72 stepside 4x4. I bought the truck new & put the BB in it in 1976. Dimple firewall slightly around clutch rod hole & use corvette power brake valve cover on left side. Everything else fits. Used corvette exhaust manifolds-had to modify xmember under engine for clearance & then gusset on under side for strength. Used all 2 1/2 exhaust pipe, but started breaking hangers. Ended up with 90 out of manifolds 18" of flex pipe & then mounted rest of exhaust ridged to frame. Every 2 years you will have to replace flex pipe, but works great. Only problem since is breaking front axles. They wern't ment for 390HP!
Good luck Rick-Ca.

71 fun · 07-12-2003, 11:54 PM

This is my repower. moved everything foward 2.5 " and redrilled all holes. cut 2 " off fan shroud and wrapped with aluminum stripthen went with a flex fan and spacer. 350 motor mounts, 350 auto trans, 3" exhaust.

midyearvet@aol. · 07-13-2003, 01:19 AM

I had to cut 2" off the schroud also-forgot.
My motor is in the stock location though. I also double flanged the x member on both sides of the oil pan so I can drop the pan without removing the xmember. I just unbolt the center piece.
I had tri-power off a corvette 400hp 427, but a little to radical off road. I now run a 600 Holley similer to what a stock 390hp would use. But also have a 730 w/vacum sec for when I want some real power. 600cfm is real under carbed.
Your Truck looks great. Rick

**Yukon Jack** · 07-13-2003, 01:16 PM

71 Fun - any more pics of your truck? Looks like an awesome engine compartment.

Some great new info on the BB swap in this post compared to when I was gathering info about 10 months ago.

**too much stuff** · 07-13-2003, 11:28 PM

Yes, it is the drivers side that is tight. I also used stock exhaust manifolds off a 77 gmc 1/2 ton 454. A little grinding like previous thread stated, but pretty minor. Back plug wire is snug also. I'm sitting on stock 350 motor mounts in the stock location. My truck is a 70, so it has the throttle rod instead of cable. If i think of more i will post it.

ozarkhippie · 07-13-2003, 11:49 PM

What fan shroud should be used? The small block 4x4, or one for a 71 72 big block 2wd.

71 fun · 07-13-2003, 11:49 PM

Yukon, just have this.

07-08-2003, 05:08 PM	#4
jamie72 Senior Member Join Date: Apr 2000 Location: madison indiana Posts: 3,836	hey josh may i can help you out,just bring up that bb and i`ll trade you a 406 i got on the stand... jamie __________________ jamie72 72 BB cheyenne -- Restoration getting started.. member #807 http://www.myspace.com/whitetailobsession www.antlertalk.com

07-08-2003, 09:39 PM	#7
Chevy409 Giddy up giddy up... Join Date: Feb 2001 Location: US Posts: 483	A few swings with the hammer against the firewall and she'll slide right in there... __________________ 72 with 69 grille and custom 73-87 stepside. BIG BLOCK 409, SM465, NP205, 3/4 axles slung under a 5" lift, 3"bodylift, 112" frame, and 35inch Pro Comp X-terrains... "BUILT NOT BOUGHT" Here's the site...

07-08-2003, 09:51 PM	#8
Class of 69 Registered User Join Date: Mar 2003 Location: Stillwater MN Posts: 1,166	I'm assuming it's the right valve cover that is too close?? Any pics to show the correct location of the needed love taps? I just acquired a 396 to "drop" in my 69 4x4, so all help with install tips will be appreciated. I like what Truck Hippy said about it fitting right in!! That is what I was "planning " on. __________________ 69 GMC K10 ..some restoration required....still..

07-09-2003, 12:15 AM	#9
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,786	big block I found that corvette valve covers with the notch in the rear helped. Mine sits in the back holes with a stock hei. It is tight, but it will go. Class of 69, if you are around grand rapids and want to check my 70 with a B.B. , let me know. Been there, done that.

07-09-2003, 12:22 AM	#11
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	For the record I put a Big Block in my shortbox that was originally a smallblock with very few problems. I did move it forward almost 2 inches so i would not have to bash in the firewall. The front driveshaft worked out alright but i also lifted it 6 inches. I am also using a 4 core radiator and a longwater pump setup, so dont be fooled by fan clearance. It was a manual shift truck so i also slid the shift pivot up. The floor hump was also cut with new holes to accomodate the relocation. You can get a cover from a big block, AT, 2 wd (there will be no existing holes) and just cut your new ones in it. The HEI fits great now and the valve covers do not hit either. Now the truck is as it should have been from the factory!! __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.

07-08-2003, 02:53 PM	#2
GMC71k20 Registered User Join Date: Aug 2002 Location: mass Posts: 1,277	how far do you have to move everything forward? do you have to cut up the floor for the shifters? what about clutch linkage?

07-08-2003, 08:03 PM	#5
Truck Hippy Registered User Join Date: Aug 2002 Location: Hickory, NC. Posts: 776	Hey guys. I put a 454 into a 72' swb 4x4 several years ago and I didn't move anything. Well I really changed the motor 2 times but the first time all I did was put it in. The second time I did mark where the valve covers came close to the firewall and before I put in the second BB, I gave it a little love tap to make sure the motor could move with out hitting. The motor fit, no problems. I even had HEI in it. This is the only 4x4 I have put a BB in.

07-08-2003, 09:19 PM	#6
GMC71k20 Registered User Join Date: Aug 2002 Location: mass Posts: 1,277	i wouldnt mind going with an electric fan and my rear driveshaft looks like hell and has a little warp to it so maybe that wouldnt be too bad.

07-09-2003, 12:52 AM	#12
casey Registered User Join Date: Jan 2003 Location: Kelowna B.C. Canada Posts: 2,048	excuse my ignorance but didn't the 4x4s come with a big block?, why all the customizing to fit a BB in a 4x4 unless they never came with one

07-12-2003, 03:37 PM	#14
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,786	covers blue 71, no pics available, but drivers side rear lower corner is layed back to accomodate the power brake booster in a corvette (so i am told) You will know it if you see it.

07-12-2003, 04:02 PM	#15
Class of 69 Registered User Join Date: Mar 2003 Location: Stillwater MN Posts: 1,166	casey, my ignorance too!! I didn't know they were not a factory option until the chassis was loaded on the trailer and they all said " have fun getting that in there" too much stuff, I know the cover you speak of.....is it the left side that has the clearance problem?? __________________ 69 GMC K10 ..some restoration required....still..

07-12-2003, 06:54 PM	#16
Truck Hippy Registered User Join Date: Aug 2002 Location: Hickory, NC. Posts: 776	This is kinda long but its what all I ran into putting a 454 into a 72' swb 4x4 with a/c. First the motor. It was a some what stock 454 with a 69' 396/325 cast iron intake and the correct truck exhaust manifolds, stock valve covers, ect. I was trying to make the truck "look" factory, hince no chrome, correct brackets, everything except the HEI. The install was pretty straight foward but i suggest doing a few things first. On a 71-72 truck with cable gas pedel, there are 3 small bolts (see photo) that hold the gas pedel to the fire wall, these need to be made shorter. My valve cover didn't hit the fire wall, it hit one of these bolts. Next I had to grind off a small "nub" on the lower front drivers side manifold because it hit the frame in front of the motor mount. This took all of 2 minutes. Now my truck was an automatic so I tried to use a longer dipstick for the trans but it didn't work out very well so I just used to stock short one. I recomend removing the drivers side valve cover when putting in the motor. It will rub the power brake booster as it goes by. If you don't have A/C, it may go by ok. I don't have any pictures of the truck with a BB and I don't remember where to put the "love taps" but you may be able to look at a 2wb bb truck and kinda get an idea. Now these were "love taps", I didn't total loss my fire wall at all. I used a hammer with a ball end on it and a smaller hammer to hit it with. I put the ball on the fire wall and gave it a few taps. On my truck, I didn't HAVE to put them but the motor is very close and I thought it would be alot easer in the long run. I didn't move the motor foward, the truck had no body lift, I used the stock gas pedel cable. I put the motor in complete except carb, dis. cap, and brackets. Now I raised h*ll in this truck. That 454 would light up my 33x12.50's and it was a blast to drive. If I remember right this is all I had to do. I even changed the cam out with the motor still in the truck. If anybody has any questions, drop me a line at: wesbaird@charter.net I'll be happy to help out if I can. Would I do it again? You dam right! Attached Images

07-12-2003, 06:57 PM	#17
Truck Hippy Registered User Join Date: Aug 2002 Location: Hickory, NC. Posts: 776	sorry about the picture, either me or my camera can't take a good close up picture.

07-12-2003, 07:20 PM	#18
midyearvet@aol. Registered User Join Date: Jun 2003 Location: Napa, Ca. Posts: 103	I have a 427 in my 72 stepside 4x4. I bought the truck new & put the BB in it in 1976. Dimple firewall slightly around clutch rod hole & use corvette power brake valve cover on left side. Everything else fits. Used corvette exhaust manifolds-had to modify xmember under engine for clearance & then gusset on under side for strength. Used all 2 1/2 exhaust pipe, but started breaking hangers. Ended up with 90 out of manifolds 18" of flex pipe & then mounted rest of exhaust ridged to frame. Every 2 years you will have to replace flex pipe, but works great. Only problem since is breaking front axles. They wern't ment for 390HP! Good luck Rick-Ca.

07-12-2003, 11:54 PM	#19
71 fun Registered User Join Date: Jul 2003 Location: Elko,Nv. Posts: 65	This is my repower. moved everything foward 2.5 " and redrilled all holes. cut 2 " off fan shroud and wrapped with aluminum stripthen went with a flex fan and spacer. 350 motor mounts, 350 auto trans, 3" exhaust. Attached Images



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07-13-2003, 01:19 AM	#20
midyearvet@aol. Registered User Join Date: Jun 2003 Location: Napa, Ca. Posts: 103	I had to cut 2" off the schroud also-forgot. My motor is in the stock location though. I also double flanged the x member on both sides of the oil pan so I can drop the pan without removing the xmember. I just unbolt the center piece. I had tri-power off a corvette 400hp 427, but a little to radical off road. I now run a 600 Holley similer to what a stock 390hp would use. But also have a 730 w/vacum sec for when I want some real power. 600cfm is real under carbed. Your Truck looks great. Rick

07-13-2003, 01:16 PM	#21
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	71 Fun - any more pics of your truck? Looks like an awesome engine compartment. Some great new info on the BB swap in this post compared to when I was gathering info about 10 months ago. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

07-13-2003, 11:28 PM	#22
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,786	Yes, it is the drivers side that is tight. I also used stock exhaust manifolds off a 77 gmc 1/2 ton 454. A little grinding like previous thread stated, but pretty minor. Back plug wire is snug also. I'm sitting on stock 350 motor mounts in the stock location. My truck is a 70, so it has the throttle rod instead of cable. If i think of more i will post it.

07-13-2003, 11:49 PM	#23
ozarkhippie Registered User Join Date: Nov 2002 Location: Eureka Springs AR Posts: 494	What fan shroud should be used? The small block 4x4, or one for a 71 72 big block 2wd. __________________ Buy Sale or Trade 71 3/4 4x4 72 1/2 ton cheyenne 4x4

07-13-2003, 11:49 PM	#24
71 fun Registered User Join Date: Jul 2003 Location: Elko,Nv. Posts: 65	engine pic's Yukon, just have this. Attached Images

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