hot rod joe

Hello! Hey just found this forum and I am sure glad I did!! I am new to the forum and new to the hobby of street rod building. I have worked on a lot of cars over the years, but trying to make something fit or work that the car didn't come with is a different story. I bought a 1937 Plymouth P4 Dexluxe and am starting my first attempt at rebuilding it. I have successfully gotten the drivetrain out of it and now looking for a replacement to put in its place. Here is my dilemma. I have asked so many questions about what would work for my application I am wanting to achieve that I am still scratching my head about replacement parts.
I have settled on replacing the old flathead 6 with a V8 Mopar. The three speed tranny with an automatic( momma says as long as she can drive it she will keep budgeting for parts!! which means an automatic). And a Mopar rear-end, I am just not sure what kind of combinations I need?
I want a set up I can play with sometimes stoplight to stoplight, not competitively, but just for fun. But my main drive will be cross country, highway use mostly. Momma says we can drive it when we retire. So I want some HP, but I want a nice cruiser.

I would like about 400 HP, but a nice easy low RPM cruiser on the open road.
I am sure there are a lot of different combinations but I am not sure where to start. I am looking at a 383 right now with a 727 torque flite. Am I on the right track? I don't know what rear end or gear ration would be good for what I want. I am hoping someone out there has had or is having the same dilemma and can shed some light on where to look, what to consider, or solutions..

Thanks for reading this long opening letter... Joe

Archer

Hi Joe -

Welcome,.
Ya might want to narrow down what you're looking for.
We can give you our experiences, but our "preferences" may not be yours.
What body style, highway driving, is gas mileage an issue, how far "off stock" dio you want to go?
The 383 is a good motor, but if you're staring from scratch, a 440 would be a better bet and there are plenty around.

For low RPM, think 3.23 gears but like I said, your not giving us a lot to work with.

Archer

hot rod joe

Ok, i'll try and get out what is in my head:
- I would like about 400 HP
- I plan on 98% highway use, wife wants to take it cross country
- Gas milage would be a plus, but isn't a deal breaker
- My car is a 1937 Plymouth Deluxe 4 Door( tried to attach pics but they were to big)
- As far as "off stock", that is what I am trying to figure out.

Can I just bump up a cam from stock? Do I have to have a lot of machining done. I am not going to race it, but want to show off a little. What would be my advantage starting with a 440 vs 383?

I have 24" inside frame width to set this in, will that be an issue?
I know it isn't making a lot of sense, but if anyone has any ideas or would be able to give me places to go look for builds and specifications I would welcome a PM and I will send my contact #.
Thanks
Joe

wreklus

Definitely can't be too picky about gas mileage when you're talking mopar V8, haha!
For reference, I drive a Gen III 5.7 hemi in a jeep and I consider anything over 16mpg as 'good mileage'.

As has been pointed out to me, there are some really great crate engine and transmission combos out there. The advantage being that they can be shipped ready to wire up and run, and come with a warranty. The convenience does come at cost, though.

If you aren't shy with breaking down a motor completely, you can pick up junkyard late model hemis out of Ram trucks. Holley makes EFI systems for these engines that come with a lot of praise from hot rod magazines that do a lot of engine swaps.
Even running engines go for cheap because Rams are a dime a dozen at junkyards these days. This would be my plan if my hemi bit the dust.
They are cheap enough to justify going for a stroker kit and building up something that can put 400 to the wheels. Not without a considerable investment in time and effort, but it's been done often enough that there is a lot of really solid data out there now.

RacerHog

Cool Ride.. Good advise here so far... ... Neat Project... My Pops had a 37 Desoto in-line 6... Fun car. Nice riding also...
My 2 cents.. For the space to work in, I would look into a 408ci, EFI, with block hugger headers, 727 trans, Overdrive Gear Vendor, Custom fit Currie Enterprises rear end with a 3.90 or 3.80 ratio, Vintage Air System for HVAC, And some suspension and brake upgrades. Maybe a Champion of Mopar Marty Cooling system.

Welcome to the site.
Have fun, Looking forward to seeing you progress.
CHEERS

Iowan

I'm in favor of a small block as well, a 360 or a stroked version of it. There's just not a lot of room to be had and if you go big block a 383 will fit better than a 440 because the 383 is narrower.

hot rod joe

Wow, I got a lot to process, I think once I just decide on an engine, life will be a lot easier. Then I can figure out how to build it..i will probably be touching base with a few of you to get advise. Thank you for all the great information....

wreklus

Do us a solid and create a thread for your build under the "member's rides" section.
It would be great to see some pictures of what you're working with!

Archer

Joe -

Gotta go with Bob and gang.
Think small block, and a crate motor would be the most economical.

I would not, however go with a 3.90 gear if you plan on going x-country, unless opt for the Gear-Vender over-drive.
I'm using 3.90s on a 440 and while certain "OK" on the highway, having the motor cruising over 3K RPM, gets expensive in more ways than one.
3.23 would be easier all around.

Yes, you "can" just bump up the cam just a little, but matching the intake and exhaust to the cam makes a much happier camper.

Sorry, I don't know a lot about cars that old, so can't be specific on fit and stuff.

Archer

Coronet 500

Welcome.

If it were my project I'd look at buying a Dodge Dakota and transplant all the modern drivetrain, maybe a short one that is very close to the same wheelbase and drop the body over the whole frame.

Once you've got it together then the aftermarket parts for performance, safety and comfort is wide open.

Iowan

The Dakota frame might be to wide for a 30s body but using Dakota running gear is a good idea, OD trans and rear axle. 👍

RacerHog

Chop>>>>> Cut>>>>> Rebuild>>>>>
(*)V(*)

wreklus

I'm looking forward to seeing what comes of this build.
Any way you go about it, if it runs and drives, it'll be killer cool!