Converting small block truck to big block

tragic59 · Post by **tragic59** » Tue May 24, 2005 8:03 pm

I have a 67 318/727 D-200. I want it to be a 67 440/727 D-200.

I found a 68 D-200 big block truck in a wrecking yard, and I'm curious what I need to take off of it to make the conversion. It's motor is gone, but I already have the 440 and tranny in the garage anyways.

Do I need the motor mounts off the frame?

Tranny mount cross member?

Shifter cables?

I figure I need the drive shaft, right?

Anything else I'm forgetting that will make my life easier when the time comes for the swap???

Thanks.

digdoug · Post by **digdoug** » Tue May 24, 2005 10:02 pm

You need the steel mounts that bolt to the 383 truck engine,the big block 727 tranny,big block tranny lines,big block radiator and shroud.

Post by **Hobcobble** » Wed May 25, 2005 7:07 am

Its probably a good idea to switch the shift selector
arm from your SB 727 to the BB 727 as they're specific
to the cable/dash shift set ups. You'll need to come
up with a kick-down linkage if your BB set up doesn't
have one on it now.
John

Jeffc · Post by **Jeffc** » Wed May 25, 2005 2:04 pm

You will need the big block raditor, it sets farther foward than the small block one......
engine mounts on the engine side, the bb ones make it fit very nice, smb ones can be made to work but don't fit right and may need some work to fit......no change to frame mount side...
Drive shaft should swap as long as splines line up in the tail shaft.....
cable shift stuff will all swap except arm on trans
and kickdown arm as John said...

digdoug · Post by **digdoug** » Wed May 25, 2005 7:56 pm

I forgot that you will want to grab the throttle rod and under hood wireing,as they too are different on a big block truck.Also pickup ex. manifolds are a good idea.The post 72 center dump style off 400,440pickups flow best.Or maybe try a set of block huggers like Jeff C did.

Doug

dusty · Post by **dusty** » Wed May 25, 2005 8:45 pm

i made the sb radiator work by spacing it forward and switching outlet side,depending on witch water pump housing you have

Ramit · Post by **Ramit** » Sun Jun 12, 2005 11:03 pm

My 68 power wagon has a 383 in it from a 2wd truck. It was a bolt in swap right down to the oil pan. You will need B series trans and converter, trans lenght and crossmember identical, a good triple core radiator, truck specific big block exhaust manifolds and headpipes, throttle linkage and you have it all. Big blocks RULE!

vance4 · Post by **vance4** » Mon Jun 13, 2005 1:57 am

What is the difference in the underhood wiring between the small and big block V-8's? I don't know where to find the big block wiring.... We are currently doing this same swap, but I had not thought about the wiring being different..... so info please.

Guest · Post by **Guest** » Mon Jun 13, 2005 2:13 am

What year is yours? Bout the only difference is the distributor being in the front compared to the rear on teens.

vance4 · Post by **vance4** » Mon Jun 13, 2005 3:50 am

My truck is a 1971 and the 440 is a 1970....the distributor is up front on the 440 and I believe it was in the rear of the 318. So are you guys thinking that some of the wiring will just not reach? Or are other problems lurking in the shadows? Thanks for the reply.......

Post by **cowboy** » Mon Jun 13, 2005 6:48 am

vance, your right the SB dist is in the rear , & as far as I know the wires are just to short when I did mine years ago I just splice them & all was well

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Converting small block truck to big block

Converting small block truck to big block

radiator swap