big block 4x4? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BurnoutNova · 11-10-2004, 02:42 AM

well, i know theres such things as 4x4 big block trucks, (67-72) but, did they come that way from the factory ever? i dont think ive ever seen one that was said to be factory. if there was never any, why wasnt there??? to heavy up front?

i have a friend who has a gorgeous 70 K-5, thats all original, and he found a 71 cheyenne 20 with a 402, and th400 but has a rusty body.

anyway, does it take a special oil pan or motor mounts to put a big block in a K-5???

im just wondering,

so any info on big block 4x4's would be great!

zach

Dean · 11-10-2004, 07:57 AM

None from the factory, but it can be done as you have seen. Several members on here have done the swap.

Longhorn4x4 · 11-10-2004, 09:41 AM

Until they started building the K-30, they did not have a front axle that could take the power. They also didn't put a 400 transmission in a 4x4 until the mid 70's, so they didn't have an automatic that could handle the power. I think somewhere around 82 was the first year for a 454 in a K-30. I ordered an 84, but it was never delivered.

I have a 454 block sitting in my 70 Longhorn that I converted to 4x4, it sits on a 70 Dana 44 right now, but I'm swapping in either a Dana 70 (needs a lot of work, it is military bigsix pattern with drums) or if I get a good deal, a Dana 60.

I'm using the crossmember from a wrecked 71 K5, with the original mounts. But I am going to modify the crossmember for more pan clearance.You may have problems with valve covers hitting the firewall, the heater box, or the brake booster. An HEI distributor may also hit the firewall.

I suppose you can get by with a Dana 44, but you will have to be gentle with it.

You'll need either a 465/205 stick shift setup, or a 400/205 automatic setup, unless you never plan to use the power.

A good add-a-leaf for the front will get the ride height where it should be if you're not running a lift kit.

smokekiki · 11-10-2004, 10:22 AM

Any trans shop that builds performance trans can hook you up with a th350 that will handle a 454.

**Yukon Jack** · 11-10-2004, 11:16 AM

A passenger car bb oil pan is supposed to fit better than a truck bb oil pan. Or you can switch to a 73-87 engine crossmember and get better oil pan clearance and easier fitting headers.

Looks like your best bet for fitting a bb in a 67-72 4x4 is to move the engine forward about 2". I modified my firewall considerably but some don't have to do more than bang in the firewall a bit. Here's my site with my info on fitting a 454 in my 69 K20.

http://yukon.b0xen.us/bigblockfitmentweb.html

orangeuavol · 11-10-2004, 12:43 PM

Put a 402 BB in my '72 K5. Used the original cross member and SB mounts. Will have to fabricate some on the firewall for valve cover clearance. Look at my PICs in my signature and you'll find a few of the test fit and finished BB.

elk hunter · 11-10-2004, 01:00 PM

i have a 72 k20 with a 402 and no mods to the firewall. i used late model o-ring valve covers on 66 427 heads. lots of clearance and no leaks

my th350 holds hp just fine.... smokes the tires through three gears!!! :p btw thats with 35'' tires and a locker too

**Canadian694x4** · 11-10-2004, 01:12 PM

Quote:

Originally Posted by Longhorn4x4

Until they started building the K-30, they did not have a front axle that could take the power. They also didn't put a 400 transmission in a 4x4 until the mid 70's, so they didn't have an automatic that could handle the power. I think somewhere around 82 was the first year for a 454 in a K-30. I ordered an 84, but it was never delivered.

I have a 454 block sitting in my 70 Longhorn that I converted to 4x4, it sits on a 70 Dana 44 right now, but I'm swapping in either a Dana 70 (needs a lot of work, it is military bigsix pattern with drums) or if I get a good deal, a Dana 60.

I'm using the crossmember from a wrecked 71 K5, with the original mounts. But I am going to modify the crossmember for more pan clearance.You may have problems with valve covers hitting the firewall, the heater box, or the brake booster. An HEI distributor may also hit the firewall.

I suppose you can get by with a Dana 44, but you will have to be gentle with it.

You'll need either a 465/205 stick shift setup, or a 400/205 automatic setup, unless you never plan to use the power.

A good add-a-leaf for the front will get the ride height where it should be if you're not running a lift kit.

Do you have any pics of your setup? Would love to see it....sounds pretty cool.

**too much stuff** · 11-10-2004, 07:23 PM

When i did mine, i used the corvette style valve covers with the notch in the rear for a little more clearance.

11-10-2004, 02:42 AM	#1
BurnoutNova Registered User Join Date: Mar 2004 Location: CA Posts: 2,057	big block 4x4? well, i know theres such things as 4x4 big block trucks, (67-72) but, did they come that way from the factory ever? i dont think ive ever seen one that was said to be factory. if there was never any, why wasnt there??? to heavy up front? i have a friend who has a gorgeous 70 K-5, thats all original, and he found a 71 cheyenne 20 with a 402, and th400 but has a rusty body. anyway, does it take a special oil pan or motor mounts to put a big block in a K-5??? im just wondering, so any info on big block 4x4's would be great! zach

11-10-2004, 10:22 AM	#4
smokekiki Mike Join Date: Jan 2003 Location: west chester pa Posts: 2,473	Any trans shop that builds performance trans can hook you up with a th350 that will handle a 454. __________________ 70'c/10, 71 suburban4x4 402bb, 72suburban 4/6 drop, 72k/5 4x4 blazer 4" lift 35 tires

11-10-2004, 11:16 AM	#5
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	A passenger car bb oil pan is supposed to fit better than a truck bb oil pan. Or you can switch to a 73-87 engine crossmember and get better oil pan clearance and easier fitting headers. Looks like your best bet for fitting a bb in a 67-72 4x4 is to move the engine forward about 2". I modified my firewall considerably but some don't have to do more than bang in the firewall a bit. Here's my site with my info on fitting a 454 in my 69 K20. http://yukon.b0xen.us/bigblockfitmentweb.html __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

11-10-2004, 12:43 PM	#6
orangeuavol GO VOLS! Join Date: May 2001 Location: Knoxville, TN Posts: 724	Put a 402 BB in my '72 K5. Used the original cross member and SB mounts. Will have to fabricate some on the firewall for valve cover clearance. Look at my PICs in my signature and you'll find a few of the test fit and finished BB. __________________ http://1972blazer.shutterfly.com/<= blazer build pics It's called golf because all the other four letter words were taken. It's easier to ask for forgiveness than for permission.

11-10-2004, 01:00 PM	#7
elk hunter Registered User Join Date: Dec 2003 Location: oregon city, or Posts: 164	i have a 72 k20 with a 402 and no mods to the firewall. i used late model o-ring valve covers on 66 427 heads. lots of clearance and no leaks my th350 holds hp just fine.... smokes the tires through three gears!!! :p btw thats with 35'' tires and a locker too __________________ yeah, but how's it wheel?

11-10-2004, 07:57 AM	#2
Dean Senior Member Join Date: Jan 2000 Location: Cincinnati, Ohio Posts: 1,492	None from the factory, but it can be done as you have seen. Several members on here have done the swap.

11-10-2004, 09:41 AM	#3
Longhorn4x4 Registered User Join Date: Oct 2002 Location: Murfreesboro Tennessee Posts: 58	Until they started building the K-30, they did not have a front axle that could take the power. They also didn't put a 400 transmission in a 4x4 until the mid 70's, so they didn't have an automatic that could handle the power. I think somewhere around 82 was the first year for a 454 in a K-30. I ordered an 84, but it was never delivered. I have a 454 block sitting in my 70 Longhorn that I converted to 4x4, it sits on a 70 Dana 44 right now, but I'm swapping in either a Dana 70 (needs a lot of work, it is military bigsix pattern with drums) or if I get a good deal, a Dana 60. I'm using the crossmember from a wrecked 71 K5, with the original mounts. But I am going to modify the crossmember for more pan clearance.You may have problems with valve covers hitting the firewall, the heater box, or the brake booster. An HEI distributor may also hit the firewall. I suppose you can get by with a Dana 44, but you will have to be gentle with it. You'll need either a 465/205 stick shift setup, or a 400/205 automatic setup, unless you never plan to use the power. A good add-a-leaf for the front will get the ride height where it should be if you're not running a lift kit.

11-10-2004, 07:23 PM	#9
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,790	When i did mine, i used the corvette style valve covers with the notch in the rear for a little more clearance. __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto



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