I have a 1979 D100 with the 318 and 727 tranny. I had to park it last July because the radiator started leaking on me. When I went to try to get it going again, I found out that sometime during the winter I ended up with a crack in the block on the driver's side about 1/2" above the middle freeze plug. The question I have is should I try to find another motor from a junkyard, look for a short block or just get a rebuilt one? Also would the heads and everything else not included in a short block from the 318 work on a 360? I've never had to deal with this problem before and I don't want to have to get rid of my truck because of a cracked motor. I used to have a 1980 D150 with the slant six and the A-833 4 speed that I had to get rid of because I spun a bearing in it and then had other problems with it. I really like my truck and would appreciate any help in getting it running again.

 

Whether you want a salvage yard motor or a rebuilt is up to you. I personally believe buying a used engine is buying someone else's problems if you don't know the history of the engine. One thing I will tell you is when you price compare be aware that due to the crack you do not have a returnable core if you go short block or rebuilt. It will be more expensive than usual.

 

The crack is in the water jacket right above the freeze plug about where the numbers are stamped on the engine. I was told that I could use JB Weld on it and that should fix it. I was also told I could use Liquid Glass, but I would have to by-pass my heater core to use it. Would either one of these ideas work and last long enough for me to get the money for another engine?

 

my bro inlaw used jb weld on a 305 boat motor that was cracked along the water jacket it held up for a test run on it other than that i dunno how long it's lasted or did last

 

i'm gonna get my truck to my bro inlaws house to use his shop to pull the motor so i can get it cleaned up and put the three freeze plugs back in it that also came and then gonna see how well jb weld will work for me. i'm just hoping it will work long enough for me to get a new motor.

 

ive sealed oil pans with JB weld. Ive also used it to smooth over pitting on when chnaging the head gasket of an AMC 196 flathead. Another good product is called "high heat metal" or something. its usually in the same aisle as the JB weld and comes in a pill-bottle shaped container with a white screw top. Ive used that to seal manifolds - iot gets harder as it gets hotter.