302 Question-72 and 78 Blocks=same?

[electricgreen]

Are the blocks the same in 72 and 78? We finally got the Mach motor torn apart last night, and found the source of the noise. 3 of the 8 Pistons were scratched up, and there is a decent gouge in 1 cylinder wall (I didn't actually see the block, just the worst piston. A friend came over to help, I let the guys hang out-"garage time", ya know-gotta give them time to b@#$% about the wives, lol). So anyway, I don't know if a) the gouge is deep enough so that even with a .30 over bore it would be removed b) the motor is already bores .XX over (no markings on the pistons that we could find).

We still have the 78 motor sitting around, we never found a bigger bell & torque converter for it. So, could we use 72 internals (new ones, obviously. I'll post a pic of the piston later-hopefully-but I wouldn't want to re-use any of the parts, looks like there was some serious stress going on) in the 78 block? The garage is about 200 feet from where we can get the truck to, and theres a good 2' of snow on the ground, so if we have to get the 72 block out to a machine shop, it's going to be a few months. We had hoped to get the motor & tranny back in before spring!!!

 

[electricgreen]

Update

Just found out that under closer inspection in better light, the pistons were stamped with a bore. It was .30 over Sooo, hopefully someone can tell me if the 78 block will work.....

 

[brianj5600]

It may have a slightly taller deck. Everything should interchange. I heard that around 75 they started thinning the main webs and pan rail, but for a street motor it should be fine.

 

[D.Hearne]

Some of the 78 ( D8VE blocks ) have thicker walls and can be bored 60 over. This is the Lincoln block. It can be identified by the casting # and the crankshaft position sensor boss on the outside, just above the rear main. According to Ford, this block has 10 lbs more iron in it than most other 302 blocks.

 

[electricgreen]

Ok, I do know it's a Lincoln block. So we should be able to use this block? I know the Lincoln used a different crank, but we would be replacing that anyway....The heads we would be using are the DOOE-B 302 heads, if that matters.

Thanks guys!!!!!

 

[D.Hearne]

The crank in a 78 302 is the same as a 72 motor. For all intents and purposes, all 302 cranks from 68 to about 81 were the same, excepting the boss 302 cranks. Sometime around 82, Ford switched to the 50 oz/in balance cranks in the 302, then came the one piece rear main seal cranks, or they may have been done at the same time. The heads are also interchangeable from 72 to 78, except for the pedestal type rockers on the 78 heads, these just used different rockers, but the same pushrods.

 

[67bluestang]

Some of the 78 ( D8VE blocks ) have thicker walls and can be bored 60 over. This is the Lincoln block. It can be identified by the casting # and the crankshaft position sensor boss on the outside, just above the rear main. According to Ford, this block has 10 lbs more iron in it than most other 302 blocks.

D.Hearne
Thats the block i have in my coupe, D8VE. Its already .030 over and i'm considering going .060. I've also been told it will run hot if i go .060 over. Is this true? If so, maybe i'll just leave it at .030 since there's not much of a lip at the top, so a good hone should clean it up pretty good.

 

[D.Hearne]

I can't tell you for sure that it will not run hot, but just that I have a Ford 5.0 book that states that the D8VE block with the crankshaft position sensor boss, is a thick wall design, and is 10 lbs heavier than the other 5.0/302 blocks. I have one also that I have considered using for a 60 over stroker with a 3.4 crank to make a 352, but I don't know that it'll ever happen. I prefer a roller block to use with a roller cam, mucho cheaper than retrofitting a roller into a non-roller block.