4.3 in a 68 truck - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68gmsee · 08-08-2009, 04:01 PM

Question came up in a conversation with a friend. He has a 68 chevy that had a 250 six manual transmission. Engine is gone but he has a complete 4.3 engine out of an 85-86 truck that is in excellent condition.

His question was if he could use that engine in the truck and if anyone had made that swap?

14U2NV · 08-08-2009, 04:12 PM

Never done that swap, but I've always been told that the 4.3 is a 350 with the front two cylinders cut off. I would think with small block mounts it would bolt right in. Don't quote me on that, but I believe it is true. I had a 4.3 in an S-10 and it ripped for what it was. It was alot lighter than a '68 though.

Chad

**GruntMoanCough** · 08-08-2009, 04:22 PM

Haven't done it but, I think it's a good idea.
Pretty much a bolt in operation.

*b-rad* · 08-08-2009, 04:38 PM

i love the little 4.3 good deal of power for a six

68gmsee · 08-08-2009, 04:47 PM

I've never driven a vehicle with a 4.3, but I had a neighbor with a Chevy blazer that had one in it. He always talked about how it had all the power he needed.

I'm not sure how much a Blazer weighs but it should be close to what a 68 shortbed would weigh, I think???

BarryB · 08-08-2009, 04:55 PM

Well the block will bolt up to the bell housing. The motor mounts probably gunna have to check on the that because they do sit further back than on a V8. Use V8 motor stands, possibly move those back to fit the 4.3 and redrill the holes.
There are a ton of aftermarket parts for the 4.3 good little motors, If you have it and have the ambition to do it. I'd say go for it. Its worth a shot.
Be sure to take pics and do a write up so we all can see the progress.

68gmsee · 08-08-2009, 05:08 PM

Quote:

Originally Posted by BarryB

Well the block will bolt up to the bell housing. The motor mounts probably gunna have to check on the that because they do sit further back than on a V8. Use V8 motor stands, possibly move those back to fit the 4.3 and redrill the holes.
There are a ton of aftermarket parts for the 4.3 good little motors, If you have it and have the ambition to do it. I'd say go for it. Its worth a shot.
Be sure to take pics and do a write up so we all can see the progress.

Actually, it belongs to a friend... But, if he uses it, I will definitely take notes.

Longhorn Man · 08-08-2009, 05:18 PM

the 4.3 bwllhousing IS the same as small blocks.
Its been done, there's been a few people come on this board running them. They all claim to love them and say they are powerful.
The only 4.3 I have ever driven that I would call powerfull was the CPI vortec... 92 - 95... i may be off on those years, but in that era. They had plenty of power... when they ran right. They were a nightmare though.
The rest of them, I never liked. I've logged 150,000 miles on a 2001 with a 4.3, and I still say the same as I have for many years. They are slow.

lclippard · 08-09-2009, 02:16 PM

i have a 250,000 mile astro with the 4.3, and i towed 2 69 c10s to the house with it and it didnt even grunt. should be fine IN a c10

lofly'a · 08-09-2009, 03:26 PM

my grandfather had a 72 gmc with a 4.3 carbed v6 in it that me and dad swapped in 30 years ago, it was ok but not enough torque for the LWB truck. the efi versions have a bit more torque and are fine for average daily use. the good thing about them is yes they are essentially a 350 with 2 cylinders missing and that means all will interchange except the exhaust manifolds, dizzy, and other v6 only applicable parts. my wife had a 89 astro with the 4.3 for 12 years and that thing was tough as nails, and paid for itself many times over, we sold it to a school photographer in 2001 and he still drives the crap out of it with over 250k miles on the odo.

**GR8-68** · 08-09-2009, 04:03 PM

I have thought of doing this myself, but then the sound of that sbc comes to memory and the 4.3 thought fades away, but I say go for it and let us know how the conversion goes together

Longhorn Man · 08-09-2009, 06:08 PM

they had 4.3 V6's in 1979?

Rob H. · 08-09-2009, 06:44 PM

I had a short wheel base full size 1987 Chevy van with a TBI 4.3, it had enough grunt to hop the front wheels. Dad had a 89 longbed 1500 with the same engine, getting 2nd gear rubber with the auto tranny was a common occurance and Dad's 71. I think it'd be a great engine in one of our trucks!

**Palf70Step** · 08-09-2009, 08:45 PM

Some one on the board did one many years ago, but he is no longer on the board and I think he sold the truck. Here is his web site. I am not sure how much remains on it. He did a very nice job on it, and makes me think about doing one sometimes.

http://www.truckwithaheart.com/67chevy.htm

68gmsee · 08-09-2009, 09:08 PM

Quote:

Originally Posted by Longhorn Man

they had 4.3 V6's in 1979?

I think he may have meant a 305 GMC V6...

bhoeger70 · 08-09-2009, 09:10 PM

It should bolt right in but it will sit way back in the engine bay if you use the six cylinder mounts(I would bet there would be at least two feet or more between the water pump and the radiator). If you move it up to the v-8 mounts then you will need to make the driveshaft longer but it will sit in the engine bay better.

68gmsee · 08-09-2009, 09:11 PM

Quote:

Originally Posted by Longhorn Man

they had 4.3 V6's in 1979?

I think he may have meant a 305 GMC V6??? I don't think they had 4.3's back then.

68gmsee · 08-09-2009, 09:23 PM

Quote:

Originally Posted by bhoeger70

It should bolt right in but it will sit way back in the engine bay if you use the six cylinder mounts(I would bet there would be at least two feet or more between the water pump and the radiator). If you move it up to the v-8 mounts then you will need to make the driveshaft longer but it will sit in the engine bay better.

Oh, oh... I hadn't thought about that part. I guess it's the rear two cylinders that have been bascially cut from the 350 engine. And ,if this is the case, then the forward position would be best. That way he would only have to find a longer driveshaft and rear cross member for the trans.

I'm beginning to wonder if it wouldn't be best to trade the 4.3 for a decent 350...

classic70 · 08-09-2009, 10:15 PM

My grandpa has a 2008 silverado with a 4.3 and it is not enuff to move a full size truck with out ur foot in it at all times, it should work good with some lower gears and no overdrive.

westofb · 08-09-2009, 10:22 PM

Quote:

Originally Posted by 68gmsee

Oh, oh... I hadn't thought about that part. I guess it's the rear two cylinders that have been bascially cut from the 350 engine. And ,if this is the case, then the forward position would be best. That way he would only have to find a longer driveshaft and rear cross member for the trans.

I'm beginning to wonder if it wouldn't be best to trade the 4.3 for a decent 350...

Someone can correct me if I am wrong but I think to make the 350 (5.7) a 4.3 (262 cubes I think) they actually would have the cut the 4 center cylinders in two, then removed the center section of the motor and married up cylinders 3 and 5 and 4 and 6 to make 3 cylinders per bank. Of course they never actually cut an engine block, just cast new ones in this manner to make a 6 banger. They have the same front, rear, and motor mount holes as any sbc, and all the accessories and transmissions from a sbc will fit a 4.3. Of course it is smaller in overall length front to back, so if mounted in place of a sbc, the motor mount towers will have to move rearward to align with the 4.3 (look at any full size 88-98 chevy with a 4.3... you will immediately notice the huge, long, fan shrouds on these trucks). 1/2 ton work trucks came standard with the 4.3, they are decent little engines as long as you don't work them to hard...they are prone to developing rod knocks if over worked. Just my .02 worth.

FLDBRED · 08-10-2009, 06:22 AM

Great little motors!I have put over 300,000 miles on two different s-10 trucks with that motor

bhoeger70 · 08-10-2009, 07:35 AM

The 4.3 is the same distance from bellhousing mount to the motor mounts as a smallblock, bigblock and even a 250 straight six. It will bolt right in just if you use the six cylinder towers it will sit way back in the engine bay. I had one in a 87 c10 with 3.08 gears and a 4 speed plenty of power here in the flat country for anything I want to pull (up to about 6000lbs).

08-08-2009, 04:01 PM	#1
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	4.3 in a 68 truck Question came up in a conversation with a friend. He has a 68 chevy that had a 250 six manual transmission. Engine is gone but he has a complete 4.3 engine out of an 85-86 truck that is in excellent condition. His question was if he could use that engine in the truck and if anyone had made that swap?

08-08-2009, 04:12 PM	#2
14U2NV Registered User Join Date: Mar 2002 Location: Midlothian, Tx Posts: 156	Re: 4.3 in a 68 truck Never done that swap, but I've always been told that the 4.3 is a 350 with the front two cylinders cut off. I would think with small block mounts it would bolt right in. Don't quote me on that, but I believe it is true. I had a 4.3 in an S-10 and it ripped for what it was. It was alot lighter than a '68 though. Chad

08-08-2009, 04:22 PM	#3
GruntMoanCough Registered User Join Date: May 2009 Location: Pemberton, BC Posts: 1,075	Re: 4.3 in a 68 truck Haven't done it but, I think it's a good idea. Pretty much a bolt in operation. __________________ My goal in life is to be as good a person as my dog already thinks I am - Unknown

08-08-2009, 04:38 PM	#4
b-rad Account Suspended Join Date: Nov 2007 Location: FT STEWART GA Posts: 509	Re: 4.3 in a 68 truck i love the little 4.3 good deal of power for a six

08-08-2009, 04:47 PM	#5
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 4.3 in a 68 truck I've never driven a vehicle with a 4.3, but I had a neighbor with a Chevy blazer that had one in it. He always talked about how it had all the power he needed. I'm not sure how much a Blazer weighs but it should be close to what a 68 shortbed would weigh, I think???

08-08-2009, 04:55 PM	#6
BarryB Senior Member Join Date: Jul 2006 Location: Blountville, Tn. Posts: 3,904	Re: 4.3 in a 68 truck Well the block will bolt up to the bell housing. The motor mounts probably gunna have to check on the that because they do sit further back than on a V8. Use V8 motor stands, possibly move those back to fit the 4.3 and redrill the holes. There are a ton of aftermarket parts for the 4.3 good little motors, If you have it and have the ambition to do it. I'd say go for it. Its worth a shot. Be sure to take pics and do a write up so we all can see the progress. __________________ We could learn a lot from crayons... Some are sharp; some are pretty;and some are dull. Some have weird names; and all are different colours;but they all have to live in the same box. You may be only one person in the world, But you may also be the world to one person. * Some mistakes are too much fun to only make once. Two rules in life. 1. Never sweat the small stuff! 2. Everything is small stuff!

08-08-2009, 05:18 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 4.3 in a 68 truck the 4.3 bwllhousing IS the same as small blocks. Its been done, there's been a few people come on this board running them. They all claim to love them and say they are powerful. The only 4.3 I have ever driven that I would call powerfull was the CPI vortec... 92 - 95... i may be off on those years, but in that era. They had plenty of power... when they ran right. They were a nightmare though. The rest of them, I never liked. I've logged 150,000 miles on a 2001 with a 4.3, and I still say the same as I have for many years. They are slow.

08-09-2009, 02:16 PM	#9
lclippard Registered User Join Date: Feb 2009 Location: huntersville, nc Posts: 144	Re: 4.3 in a 68 truck i have a 250,000 mile astro with the 4.3, and i towed 2 69 c10s to the house with it and it didnt even grunt. should be fine IN a c10 __________________ 69 burb/01 yukon chassis 65 Comet Caliente 289 4 Door Sedan 99 Millenia S (supercharged) 4 Door Sedan 02 Yamaha R6 69 swb c10 http://67-72chevytrucks.com/vboard/s...36#post3799136 building with a buddy: 85 C10 http://67-72chevytrucks.com/vboard/s...94#post3708194

08-09-2009, 03:26 PM	#10
lofly'a Registered User Join Date: May 2000 Location: Alexandria, LA 71301 Posts: 1,451	Re: 4.3 in a 68 truck my grandfather had a 72 gmc with a 4.3 carbed v6 in it that me and dad swapped in 30 years ago, it was ok but not enough torque for the LWB truck. the efi versions have a bit more torque and are fine for average daily use. the good thing about them is yes they are essentially a 350 with 2 cylinders missing and that means all will interchange except the exhaust manifolds, dizzy, and other v6 only applicable parts. my wife had a 89 astro with the 4.3 for 12 years and that thing was tough as nails, and paid for itself many times over, we sold it to a school photographer in 2001 and he still drives the crap out of it with over 250k miles on the odo. __________________ -02 avalanche (daily driver) -66 gto ragtop 389/400 (garage queen, hand-me-down from dad) -72 Tribute Trans Am (6.0LS/T56 6-speed) in progress -2003 YUKON (Wife's) -71 gmc swb fleet (current project, gonna shave everything, bags, stuff w/ 20's, gen III powertrain) -48 3100 SWB - 12/31/23 LONG TERM Project Last edited by lofly'a; 08-09-2009 at 03:29 PM.

08-09-2009, 04:03 PM	#11
GR8-68 Senior Member Join Date: Jun 2009 Location: Belews Creek , NC Posts: 4,220	Re: 4.3 in a 68 truck I have thought of doing this myself, but then the sound of that sbc comes to memory and the 4.3 thought fades away, but I say go for it and let us know how the conversion goes together

08-09-2009, 06:08 PM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 4.3 in a 68 truck they had 4.3 V6's in 1979?

08-09-2009, 06:44 PM	#13
Rob H. Registered User Join Date: Nov 2008 Location: Petersville KY Posts: 673	Re: 4.3 in a 68 truck I had a short wheel base full size 1987 Chevy van with a TBI 4.3, it had enough grunt to hop the front wheels. Dad had a 89 longbed 1500 with the same engine, getting 2nd gear rubber with the auto tranny was a common occurance and Dad's 71. I think it'd be a great engine in one of our trucks! __________________ Rob 72 C/10 (under reconstruction)(destruction ? LOL) 48 Willys CJ2A 1952 Super "A" Farmall (Grandfather's)

08-09-2009, 08:45 PM	#14
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,820	Re: 4.3 in a 68 truck Some one on the board did one many years ago, but he is no longer on the board and I think he sold the truck. Here is his web site. I am not sure how much remains on it. He did a very nice job on it, and makes me think about doing one sometimes. http://www.truckwithaheart.com/67chevy.htm __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

08-09-2009, 09:10 PM	#16
bhoeger70 Registered User Join Date: Sep 2007 Location: Grand Forks ND Posts: 434	Re: 4.3 in a 68 truck It should bolt right in but it will sit way back in the engine bay if you use the six cylinder mounts(I would bet there would be at least two feet or more between the water pump and the radiator). If you move it up to the v-8 mounts then you will need to make the driveshaft longer but it will sit in the engine bay better. __________________ "Beer is proof that God loves us and wants us to be happy" Ben Franklin 67 Chevy 1/2 lwb, 67 GMC 1/2 lwb (parts)

08-09-2009, 10:15 PM	#19
classic70 Registered User Join Date: Jun 2009 Location: Columbus IN Posts: 91	Re: 4.3 in a 68 truck My grandpa has a 2008 silverado with a 4.3 and it is not enuff to move a full size truck with out ur foot in it at all times, it should work good with some lower gears and no overdrive.



Register or Log In To remove these advertisements.

08-10-2009, 06:22 AM	#21
FLDBRED Registered User Join Date: Jun 2009 Location: CENTRAL,NJ Posts: 586	Re: 4.3 in a 68 truck Great little motors!I have put over 300,000 miles on two different s-10 trucks with that motor

08-10-2009, 07:35 AM	#22
bhoeger70 Registered User Join Date: Sep 2007 Location: Grand Forks ND Posts: 434	Re: 4.3 in a 68 truck The 4.3 is the same distance from bellhousing mount to the motor mounts as a smallblock, bigblock and even a 250 straight six. It will bolt right in just if you use the six cylinder towers it will sit way back in the engine bay. I had one in a 87 c10 with 3.08 gears and a 4 speed plenty of power here in the flat country for anything I want to pull (up to about 6000lbs). __________________ "Beer is proof that God loves us and wants us to be happy" Ben Franklin 67 Chevy 1/2 lwb, 67 GMC 1/2 lwb (parts)

Register or Log In To remove these advertisements.