318 and 904 swap into 1951 B-3

[jerseycj8]

First, thank you everyone for a really good source of information about these old vehicles.  I have worked on numerous jeep cj8 scramblers over the years, just recently completed a 88 K5 Blazer and now moving towards a 1951 Dodge B-3.  I am doing the 318 and 904 swap and am looking for detailed write-ups (with pictures even better) for the work required to do this.  A few builds I have come across talk about pieces of the swap, but have not been able to find the mother of all posts that shows step by step.  Any such thing exist?  Thanks.

[55 Fargo]

5 hours ago, jerseycj8 said:

First, thank you everyone for a really good source of information about these old vehicles.  I have worked on numerous jeep cj8 scramblers over the years, just recently completed a 88 K5 Blazer and now moving towards a 1951 Dodge B-3.  I am doing the 318 and 904 swap and am looking for detailed write-ups (with pictures even better) for the work required to do this.  A few builds I have come across talk about pieces of the swap, but have not been able to find the mother of all posts that shows step by step.  Any such thing exist?  Thanks.

Not sure a super detailed thread exists for this swap.

There are some on the web for the C series 55 and later trucks.

Do know on yours it will be off set to clear the steering box.

On the C series thats not an issue as they were designed for V8s too.

Fab your motor mounts, make a trans cross member.

Get driveshaft figured out.

Rad and trans cooler.

Trans kick down linkage or cable super important with a Torqueflite.

Gas pedal and cable.

Proper exhaust manifolds and pipes and heck your almost done.

Try on the HAMB too. 

Good Luck on the swap.

 

[48Dodger]

My truck is just such a build.

 

Dodge Diplomat front end

408 stroker (started life as a 360) 500hp

The Engine started as my Street Stock circle track race motor for my 72 Charger, but was transplanted to my 1950 B2B Land speed racer for Bonneville.

904 tranny

1996 Ford T-bird IRS

 

My threads are a bummer right now due to the changes with photobucket (haven't fixed that yet)

I'll see if I can deal with that in the next few days. 

Otherwise, dig through my past threads and you can find some posts that might interest you.

 

48D

 

[wayfarer]

There are several past threads that deal with engine swaps that could offer-up some of the details that you seek,

but you are not likely to find a complete 'how-to'  since everyone has a slightly different approach.

In addition to 48dodger you should also look at Dan Babbs Hemi swap.

Start searching.

[Dave72dt]

I've got a 318-727 combo in mine and as wayfarer said, took a different approach than Tim.  I used a Welder Series coil-over IFS and lowered the truck about 5-6 inches in front and about 3-4 in back.    What you have or use for front suspension, whether Volare, aftermarket IFS or factory I-beam will impact engine and trans placement and associated issues.  I ended up recessing the engine about 5-6 inches into the firewall and shifting it 1 1/2 -2 inches to the right for steering  column and foot clearance.  Frame crossmembers got removed for trans clearance and a new crossmember fabbed for the trans mount with a drop out section for trans removal if needed, and the frame fully boxed, front to rear.  There might be a few pics of the IFS somewhere in the truck forum, maybe a couple of the reworked firewall and trans tunnel.

 

budstruck  comes to mind, as a member, that has posted some pics of his swap, in a number of separate posts as he progressed.

[Charlie Stephenson]

You have my attention -- I have a 265 flat head-tri-power-direct drive cam-vertex-spitfire head-940-dusted rear end w Chrysler disk-shoehorning into a 34 Plymouth PE 2 door.  Build --------- want a T353 Chrysler Flat Head. Charlie Stephenson

[jerseycj8]

12 hours ago, 48Dodger said:

My truck is just such a build.

 

Dodge Diplomat front end

408 stroker (started life as a 360) 500hp

The Engine started as my Street Stock circle track race motor for my 72 Charger, but was transplanted to my 1950 B2B Land speed racer for Bonneville.

904 tranny

1996 Ford T-bird IRS

 

My threads are a bummer right now due to the changes with photobucket (haven't fixed that yet)

I'll see if I can deal with that in the next few days. 

Otherwise, dig through my past threads and you can find some posts that might interest you.

 

48D

 

Also got my donor motor and trans from a Diplomat (1986).  Any chance you have any sketches of the motor mounts and crossmember you built?  I only ask because I have not ventured into welding as of yet, but know a couple of good fab guys.  Would prefer to have pieces fabricated while i am working on other stuff if possible.

[Plymouthy Adams]

11 minutes ago, jerseycj8 said:

Also got my donor motor and trans from a Diplomat (1986).  Any chance you have any sketches of the motor mounts and crossmember you built?  I only ask because I have not ventured into welding as of yet, but know a couple of good fab guys.  Would prefer to have pieces fabricated while i am working on other stuff if possible.

did you pause on removing the engine to take measurements of the motor mounts in width , distance from firewall and height when you removed the engine.  The engine should also have single through bolt engine mounts...these are so easy to retrofit.   hopefully you remembered to also grab the mount cradles....makes fab so easy..

[Dave72dt]

Without the mounts and cradles  or changing the suspension setup from the Diplomat , you may be looking at mounts similar to what I did.  A search for Fatman Fabrication IFS started  by alboton back in 2010 has some pics of my mounts, IFS and firewall recess.  I'd provide a link if I knew how to do it.

[48Dodger]

I used the original motor mounts of the Diplomat IFS.

locating the whole cross member in a level fashion helps account for the 3 degrees of slant back to the rear axle.

I've duplicated this build several times and built a jig that I use to locate the cuts to the frame.

The cuts to the frame allow me to get the angles correct and maximize the intended use of the torsion bars.

in other words the tension applied to the bars for ride height and suspension performance.  I discovered early

on that many (ie ford guys) had "used" the torsion bar tensioners to raise and lower the front end height, negating the intended performance of torsion bars. 

There really is only about 1.5 inches of preferred tension use...or "for best results".

So making the cut to the frame really is important to get good ride response.    

And like other have said....knotching the firewall is required. For me, weight distribution was the motivation. If I had not reworked the firewall, the weight distribution would have been off.

Gotta keep all four paws firmly to the ground.

 

48D  

[jerseycj8]

20 hours ago, Plymouthy Adams said:

did you pause on removing the engine to take measurements of the motor mounts in width , distance from firewall and height when you removed the engine.  The engine should also have single through bolt engine mounts...these are so easy to retrofit.   hopefully you remembered to also grab the mount cradles....makes fab so easy..

I bought the engine already removed from vehicle, so no luck there.

[jerseycj8]

On ‎4‎/‎5‎/‎2018 at 4:40 AM, 48Dodger said:

I used the original motor mounts of the Diplomat IFS.

locating the whole cross member in a level fashion helps account for the 3 degrees of slant back to the rear axle.

I've duplicated this build several times and built a jig that I use to locate the cuts to the frame.

The cuts to the frame allow me to get the angles correct and maximize the intended use of the torsion bars.

in other words the tension applied to the bars for ride height and suspension performance.  I discovered early

on that many (ie ford guys) had "used" the torsion bar tensioners to raise and lower the front end height, negating the intended performance of torsion bars. 

There really is only about 1.5 inches of preferred tension use...or "for best results".

So making the cut to the frame really is important to get good ride response.    

And like other have said....knotching the firewall is required. For me, weight distribution was the motivation. If I had not reworked the firewall, the weight distribution would have been off.

Gotta keep all four paws firmly to the ground.

 

48D  

Can the swap be completed without modifications to the firewall.  Seems that a few people indicate that moving the radiator forward would avoid firewall modifications. 

[Dave72dt]

You may be able to using the stock suspension and a front sump oil pan.    Doing a mock up of all the parts may give you the answer.  Moving it forward or rearward , either will require some fabrication and problem solving.  Moving it rearward for me gave me a better front to rear balance and room for the radiator to sit behind the front support.  Moving it to right gave me more room for steering, pedals and my big feet in the cab and a again a better weight balance since most of it's road time will be driver only.