ENGINE SWAP 318 to 440

[nealsdodges]

I have a 1967 Coronet with a 318 poly/727 combo. I want to install a 1974 440/727 combo that came out of a 1973 motorhome. Will it work with any major changes besides motor mounts? HELP

Only 25,000 on 440

902 heads on BB and tranny has a parking brake drumb. Can I replace the tail of the tranny?

 

[426HemiCharger]

put "906" heads on it and ad a few degrees of advance on the distributor. Then buy a K&N Oil Bath air filter and slam it on there. Get a "178" Intake and put a Cater AVS on there.

 

[69 Runner]

The 452 heads on it are fine. Be aware that if they need a valve job you will probably lose the induction hardening that's done to the exhaust seats. If you really want it to fly, bump the compression up to about 10:1, install one of Bob's cams, and run a Six Pack (or six barrel for a Plymouth) on it.

The isolators for the mounts may be the same for big block and small. They are for a 69. The plates on the motor are different tho. Trans mount is the same. You'll have to stretch the distributor and coil wires (unless you go with the six pack, then the coil wires may reach) and obviously change the exhaust. Assuming there is a 904 behind the 318 then you'll need a different (read shorter) drive shaft. Also, you may have to deal with a radiator that is to small, and might have the inlet and outlet in the wrong place. Lastly don't forget about your suspension.

 

[Meep-Meep]

You will need the 440 motor mount brackets, engine compartment wiring harness (or modify yours to fit new coil location), possibly a radiator if the 318 water inlet is on the pass side. Since you have the 727 the drive shaft will be the same length. You probably don't want to mix up the converters because the 440 should have an externally balanced setup (cast crank) with big weights on the converter and the 318 probably has no external weights.

In case you are thinking of future upgrades, the aforementioned 906 heads and AVS are good but the closed chamber 915's would be better because you will have the same port but add a bit more compression to your 8.0:1 440 (I'm assuming it's stock). The closed chamber 516's with 2.08" / 1.74" valves are fine too even though the ports are not as good. The approx .5 of compression increase will outweigh the port for street drivability. It's been covered here many times, but head work is expensive so choose carefully. You can easily sink $500.00 or more in seats and guides and a valve job and approach big money if you really go nuts with new valves, springs and pocket porting. The heads you have (346 or 452's I'm guessing), if they are good, may be your best bet because of the factory hard seats. You can always use a steel shim head gasket and get nearly .5 point of compression increase there. If you go with more cam pick one that will be compatible with the low compression.

 

[Elvad]

Wow, I'm new here but, damn..The motorhome motors are different in many ways small plugs etc. but if you have car big block mounts you are all set (save the rest of it, its stupid rare) Is this an old 413 RB motor with cable shift and parking(drum) brake motor home short tailshaft housing tranny??..also 516's have 1.60 exhaust valves closed chamber design. They are the OLD early 60's closed chamber small valve heads...

 

[Elvad]

www.440source.com

Brand New Custom Built Aluminum Heads for less than $1000.00 a pair check it out!!

 

[69 Runner]

346 heads did NOT have the induction hardened seats in them. Only the 452's did. "Motorhome" motors had several different heads. There was the really odd ones that had the tall water pump housing that attached to the front of the head (as well as to the block). Then there was a head that wasn't like that, but had the small plugs due to the "steam pockets" that ran around the plug. This is of no consequence unless you have the block with the extra holes, and the matching head gaskets. Then there was a head that didn't have the WP housing attachments OR the small plugs.

Lastly, not all 915 heads had 2.08/1.74 valves. Some had 1.60 exhaust valves just like the 516s. You can have the 1.74's installed in either head, but they will require some bowl work because of the bigger valve. Also, there are some racers who swear that the 516 head has more meat in the ports, and are much better for porting than a 915. Some claim they will make more power. But to hog them to that point would NOT be cheap.

 

[Meep-Meep]

346 heads did NOT have the induction hardened seats in them. Only the 452's did.

I have heard reports from some automotive machinists that hardened seats started showing up as early as 71-72 based on how the seats respond to the stone or cutter.

 

[69 Runner]

I should know better than to say "never" when Mopars are concerned, but supposedly 346 heads didn't have hardened seats

 

[426HemiCharger]

put "906" heads on it and ad a few degrees of advance on the distributor. Then buy a K&N Oil Bath air filter and slam it on there. Get a "178" Intake and put a Carter AVS on there.

Sorry but you know what I mean, a Carter carb