318 to 440...am I thinking of everything?

[Danj96221]

So I'm in the process of restoring a '71 Charger 500 with a 318/904 combo, and one of the upcoming projects is a big block swap. I've been applying my google-fu to the subject on my spare time for a couple weeks, and wanted to make sure I'm not forgetting anything before I get set up to do the actual job. Preparation is 99%, etc etc.

So I have a 440 and 727 from the same late 70's motorhome. I'm currently rebuilding both. I believe I also need a new driveshaft, new rear end, new rear springs, upgraded front disc brakes, bigger radiator and new cooling fan, new throttle cable, schumacher engine mount adaptors and new torsion bars. Whew!

Am I forgetting anything?? I'm working with a motorhome engine/tranny and was going to shop-order a new Dana 60 rear, but I've heard some people say it's better to get a wrecked, big-block parts car and convert from that since you'll have everything in one place. How beneficial is that, or can I do this swap with what I got? I want to do it right the first time

[randy73]

If you have an 8 3/4 rear, that should work well I think, but I will let the guru's chime in. You will need a BB wiring harness, looks like SB and BB's for your year had different part numbers.

[cudaken]

 My first thought is a different 727. I have heard a few times the trail shaft will not work in a car.

Yow will need a new throttle cable, mounting bracket, trans kick down linkage and maybe a rear transmission cross member?  

Cuda Ken  

[A383Wing]

throttle cable, PS brackets, exhaust will be different

[Kern Dog]

My 70 was a 318 car. I kept my stock throttle cable when I switched to my first 440. You will need the BB brackets though. The metal motor mount brackets are BB specific. Trans cooler lines are different but can often be bent & stretched to work. Trans shift linkage has a few differences between 904s and 727s. If you can cut and weld, you can fab up what you need. The trans mount is the same, crossmember too. Drive shaft can be shortened and will work. If the car has an 8 1/4" axle, you can get by awhile before looking for an 8 3/4" axle. No need to get a Dana unless you have $ 1500 or more burning a hole in your pocket. I have a 440/493 & 727 and my 8 3/4" axle is still holding up fine.
If you have a 26" radiator, you can have the hose nipples moved to work with the BB water pump. Otherwise, a new BB specific radiator is the way to go. The 318 wiring will be shorter for the distributor & coil so you'll need to extend those wires. The water temp and oil pressure wires are close enough to work. ALT wiring is the same length.

[RallyeMike]

You can definitely re-use the existing 318 throttle cable.

If you already have disk brakes, they are the same whether it s a 318 car or 440 car, so you can get by fine unless you are looking for something more in performance.

This swap has been covered a hundred times here = lots more info can be found using the search function.

[Danj96221]

Thanks for all the replies. And in reply to Rallyemike, I already did do a search. A lot of threads cover it, but it's hard to find a complete, comprehensive list of everything that's required. It seems everyone's list includes something slightly different This helped though.

[Cooter]

That MH trans have the long tailshaft?
a picture of engine and trans from the side would clarify.

A 'list' would depend on how well you can fabricate..That's why some folks lists are shorter than others.
if you have to buy EVERYTHING then, your list will be longer.

[Dino]

If you need to do all this work and need a trans, you may want to consider installing the 508 and have an extra gear.  Paul G did it on his 3rd gen.

This all depends on what you use the car for of course.