Are All Blocks Really Same?

[mackattack3]

I've heard for years all mack blocks are same. I've have block for '93 350 E7 had electronic injection pump. Now I have 98 E7 427 that has a cracked block, has same style pump. Can anybody tell me if I use block for 350 with all parts from 427, is this gonna work??

[rhasler]

I've heard for years all mack blocks are same. I've have block for '93 350 E7 had electronic injection pump. Now I have 98 E7 427 that has a cracked block, has same style pump. Can anybody tell me if I use block for 350 with all parts from 427, is this gonna work??

Start by checking your casting numbers.

[mackattack3]

Ok I have the casting numbers. The 350 is 239GB5502M and the 427 is 239GB5518M. Help please..

[rhasler]

I can't tell you what the differences between the castings are, but since the casting numbers aren't the same there should be differences in the blocks. They sometimes change castings to make improvements, sometimes this will have an impact on interchangeability, usually it is to add strength to a weak area, to add a threaded boss, or to incorporate an improvement of some kind. This was the case when Mack changed the blocks for the E-Tech engines to relocate the coolant port for the air compressor, which in it's original position was susceptible to plugging with debris floating in the cooling system. The E7 PLN engines all had oil cooled pistons, 4 7/8" bore and 6 1/2" stroke. I think they should be intercahngeable, but take plenty of time to make sure there aren't any coolant or oil passages plugged on one that aren't plugged on the other and take plenty of measurements on both blocks to make sure that any previous boring procedures are not overlooked.

[mackattack3]

Thank you, rhasler. We are going to inspect them real careful. I have a couple of good mechanics, just in case one of us miss somethingm the other one might catch it. Thanks for your info, makes me feel like its worth the effort..

[fjh]

Thank you, rhasler. We are going to inspect them real careful. I have a couple of good mechanics, just in case one of us miss somethingm the other one might catch it. Thanks for your info, makes me feel like its worth the effort..

In My H,O As long as your 350 engine was a vmac engine what you want to do should work ,scrutinize All the bolt locations and oil and coolant locations and make sure everything is there for your application including the water pump and oil cooler mounting!

Just my 2 cents

[mackattack3]

In My H,O As long as your 350 engine was a vmac engine what you want to do should work ,scrutinize All the bolt locations and oil and coolant locations and make sure everything is there for your application including the water pump and oil cooler mounting!

Just my 2 cents

All cents appreciated.

[rhasler]

I looked at a couple of non-VMAC engines and both have casting number 239GB5518M, but they appear to have the oil supply port used for the Econovance valve in the block.