I just got hold of a 1969 Q-code Mustang, the engine that came with the car has C7ME-A on it.
The block has not got the big C welded on the back. Is this a service block?
The block is STD bore,with correct Heads and Intake Manifold,Crank is 1U.
Can some one exsplain to me what a service block is?
Are they stronger than the oiginal CJ blocks?
No engine # found as yet,are they stamped always in the same location?
I don't believe many service blocks have the casting number on them. Service blocks were over the counter replacements and would have had the same characteristics as original blocks. If the block doesn't have the C or A scratch on the back it may be a bored 390 block. The 1U crank is a early 428 crank and would not have come in a 69 engine. You should have had a 1UB crank in a car that late.
Pop the center soft plug on the passenger side and see if 428 is cast into the water jacket on the floor between the cylinder liners. Also, look at the oilfilter boss and post the date code.
The CxME, CxME-, and CxME-A markings were found on FE/FT blocks through 1970, though a growing proportion of 1969-70 FE/FT blocks had no CxM... type identifiers on them at all, but were blank. The CxM... identifiers basically lost meaning on the blocks when the FT came on the scene in 1964 and complicated foundry operations with a greater variety of molds, and the markings had no significance to after that.
Actual block identification is shown on the flywheel face of the block, and since yours had no A scratch or C scratch or S scratch on the face, it is most likely a regular 360/390 block. There remains a chance it is a 428 block, as exceptions are not rare. A drill bit test and also a water jacket text inspection may show it is a 428 block. Reinforced maincap webbing may also be present, though many early CJ engines got regular "A" 428 blocks without the reinforcements. It seems that once the SCJ engine was released in November of 1968 all 428 blocks got the "C" marking which indicated reinforced webbing.
The 1U crank was used on all 410/428/PI/CJ engines until mid-November 1968, and on PI engines thru 1970. They are balanced for the lighter weight pistons that don't say "428 Super" on the sides near the wrist pin bore. The other 428 cranks are simply balanced for heavier pistons or heavier pistons/rods found in CJ and SCJ engines during the SCJ era.
Ribs started showing up on any FE/FT block around 1971, gradually becoming more common as the years passed, and though they have a stronger look, they don't look exactly like an original car block, hence the term "service block" when dealing with ribbed FE/FT blocks. In fact, ribbed blocks are simply a later FE/FT block which was generally found in a pickup truck. True "service 428" blocks were often marked with a "CX" sand scratch or an "X" sand scratch on the flywheel face of the block, and were common in 1971-later industrial 428 applications, as well as available at the counter of your local Ford dealer in the 1970s.
