318 to 318 swap

[06Daytona]

The 318 in the Challenger is still smoking so I've decided to throw the 318 from the Cuda in for now. I'm going to throw the 4 bbl intake from a 340 on the engine and just swap the carb from the Challenger engine to the Cuda one. The Cuda engine isn't smoking at all and I don't want to spend much on it before it goes in the Challenger. I have a set of stock heads from a 73 Duster 340 where the intake came from but one of the rockers is cracked so I'd need to swap it.
Would it be less hassle to just swap the intake/carb and call it good with an engine that I know is going to last a few years, or should I swap the heads as well and hope that they're ok? I'd swap the whole 340, but it has a bad frost plug and I don't want to end up doing a complete rebuild.
The heads on the Cuda 318 are 178s and the 340 heads are 188s. I'm not sure what the heads on the Challenger are, but I don't want to take anything off the Challenger that might cause more blue smoke. I don't have a leak down tester, so I can't check valve seals etc on the heads.
I know the ports on the 340 intake aren't going to match with the 318 heads but I want to keep the headaches to a minimum.

[Super Blue 72]

When does the Challenger 318 smoke?  If you run it, warm it up, then let it sit and then start it up after a minute or two then start it up and see a puff of bluish smoke often times it's the valve seals.    I didn't get smoke coming out at acceleration, just at start up after it sat when it was warmed up.

[06Daytona]

It smokes a little when I first start it and keeps smoking when it's warm and I get a good puff when I accelerate and decelerate.

[Super Blue 72]

Starting not to sound like valve seals, maybe rings.  Maybe someone else will chime in.

You sure that the puff at acceleration is oil and not fuel?  Black or blueish smoke?

[06Daytona]

It's blue. My exhaust tips are covered in black slime and I had my sheet metal guy follow me and tell me what color the smoke was at different times.
I put the 340 intake on the 318 and painted it up all perdy so I'm just going to throw that in for the time being. If I'm going to build an engine for it it's going to be a 440. I already told my wife that I want to find one for it.

[Super Blue 72]

Sounds good! 

BTW, love the dog in your avatar!!!!

[67vertman]

Sounds like the original 318 is just plane worn out.  I bet if you did a compression test they would all be below 50. 

Just put the other 318 in it and have fun until you build your 440.......thats what I am doing.  Of yeah my 440 is built, I just need to gather more parts for the rear end and trans swap, and then it will be time to put them all in.

here is a picture of my 440.

[jimynick]

You didn't elaborate on the condition of the 340, other than it has a bad frost plug. That's a 15 minute repair with the engine out of a car, so why not change all the frost plugs, 1-2hrs and put it in? "If it ain't broke, don't fix it" kinda thing. 

[06Daytona]

The 340 turns over, but wasn't running well when I picked up the Duster. It would run for a few seconds and then die, so I don't know what shape it's really in. I bought it to rebuild the 340 and throw it in my Cuda, but the Duster is matching numbers, so my wife bought me another 340 to rebuild instead. If I pulled the 340 I would want to pull it apart and check to make sure I wasn't going to have problems with it once it when in the Challenger, but I told my wife before I bought the Challenger that I wanted a big block for it when the 318 died. With the Cuda in the shop getting a new body I don't want to spend any more than I have to on the Challenger right now. Once the Cuda is done I'll concentrate on the Challenger unless a 440 falls into my lap for cheap.