230 vs 251

[bilfman]

Me again....

I am at a crossroad for my 1947 ffpw resto. I am looking to rebuild over winter an engine for my truck. My current truck has a running 230 in it, I am wanting to put this into a 1946 wdx that I plan on selling next year. The 230 in the non runner has a trashed rod and the crank for sure needs some work. So I am looking for a complete 230 that i can use as a rebuild donor. This way I can use the existing 230 and the donor to provide all the parts needed for a full machine rebuild. Seems simple, but here is the issue.

Ok so up here in Canada the 23" 230 block appears quite hard to come by. I have a seized 25" flathead and a local wrecker has 20+ of these in various year/configurations. pickups, dumpers, gensets. So I have at my close disposal a plethora of 25" blocks, starters, manifolds, parts etc..

So my thinking is to go with a 25" 251 rebuild, due to the large amount of them around here and put that in the 47. So I have a few questions.

Are there any better 251's to go with?? Year / vehicle wise?

Any to stay away from?

Any reasons to keep the 230 over the 251?

While doing the rebuild any for sure do's any for sure don'ts?

Any other information for you experienced PW/Dodge owners is greatly appreciated as well. This is my first Dodge product and I have never worked on anything of this vintage. I am an experienced mechanic and restorer, but have been a GM muscle car and GM truck man for the past 30 years.

I understand that there will be some modifications needed to get the 25" block in the truck. Grill, rad moved and such. That shouldn't pose much of a issue. Is there anything out to watch for if I do this swap?

Any assistance steering this ship is really appreciated.

[Gordon Maney]

Are there any better 251's to go with?? Year / vehicle wise?

I don't think so.

Any to stay away from?

I don't think so.

Any reasons to keep the 230 over the 251?

Originality appeals to many and may affect resale value.

While doing the rebuild any for sure do's any for sure don'ts?

Be sure to use a competent, trustworthy machine shop in the evaluation and machining of your components. Magnaflux block and head, check for flatness of each.

Is there anything out to watch for if I do this swap?

I don't think so. Others will come along with more comment.

Any assistance steering this ship is really appreciated.

As best you can, turn only when rolling. Keep tires inflated properly. Evaluate your steering knuckles.

[horace]

one of my 47's has a bigger 6 but I don't know if it is a 250 or 265. I see the grille bars are moved forward, must be a longer block. The truck was used as a wrecker for a Buick, IH & Oliver & later GMC garage funny huh

[Matt Wilson]

I don't have any experience with the bigger block flatheads, but from what I've read, it seems that performance parts, such as dual-carb manifolds, headers, etc., are a little harder to find. I don't know if that matters to you or not, but I figured I would mention it.

[Matthew Welcher PWA]

I would stick with the 230, due to everything that you would have to change to make it a 251 truck.

[Gordon Maney]

I would stick with the 230, due to everything that you would have to change to make it a 251 truck.

What all would he have to change?

[Matthew Welcher PWA]

Replacing a 230 with a 251 engine:

In most case the easiest way to do this change would be to use many of the parts from the 230 engine. The parts that you would use would be:
-Bellhousing
-Flywheel and Clutch
-Starter
-Thermostat housing
-Pulleys
-Water Pump
-Front engine Plate(behind timing chain cover)
-Front engine mounting plate

Next, you will need to rotate the radiator core support 180 degrees and the sheet metal side panels that it bolts to will also have to rotate, right to left and left to right. Now the mounting holes for mounting the radiator on the forward side of the core support. Remount the radiator in the core support and this will move the radiator ahead about 2”. Depending on the Power Wagon model you are doing this change in, you now might have to move the top fill neck on the radiator to have it line up with the hole in the sheet metal covering it(for civilian Power Wagon, 3/4WC, or 1-1/2ton WC) The exhaust pipe also uses a square flange and you will need to use this type. If you have have an M-series Dodge you will need to modify the pipe, to connect

[Matthew Welcher PWA]

Also it might be easiest to just use a 251 radiator.

[Cheyenne Dave]

...and frame extensions for the winch...or did somebody already say that?

[Joe Cool]

Also it might be easiest to just use a 251 radiator.

Unless I'm just not looking in the right places... based on my experience trying to find a 251 radiator (my truck was missing it) I think that it would be far easier to modify one from a 230.

[pwrwagonfire]

May have already been mentioned here, but just plan on adjusting things to fit in the engine compartment.

I have the good fortune to use a 230 and a 251 on a daily basis at my work location.
The 251 seems to pull weight better, seems like a stronger motor. Also less prone to over heating in my experience than the 230 in high temps with a large load.

-T

[im02crazy]

251 Rebuild & Radiators

As you are considering the 251, we had one done last year by Jasper. The step-by-step of the full rebuild is on our site :

http://www.flyingtigertransport.com Look for the engine rebuild link.

Also, if you're looking I think we have 5 or 6 of these in the yard, and we use a local guy that can re-core these a bit deeper for even better cooling.

Please check out http://www.flyingtigertransport.com and send us a parts request on the form. Mike will check the yard.

Best of luck on the rebuild- I'd love to try one myself as long as you have a good shop to do the machining, and a good parts and spec manual.

Unless I'm just not looking in the right places... based on my experience trying to find a 251 radiator (my truck was missing it) I think that it would be far easier to modify one from a 230.