Thread: NEWBIE w/ some 390 block ????

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Hello Folks,

I am new to the forum and have some general questions. I have had past experience with small block fords and I am now going to venture into the FE world.

I would like to build a 390 for eventual use in a 67 Mustang. I have been looking at the availbel blocks on ebay and see some have an X in the lifter valley and some that are identified as a GT block.

So, what does the X signify and is there in fact a distinct "GT" block?

If so, what is the difference between a GT and non-GT block?

What is a reasonable price for standard bore 390 blocks?

If possible I would also like to find a block as close to the date of manufacture for my Mustang and a block from a mustang.

Is the correct casting code for a mustang "z"?
Would Mustangs have had "A" codes?

Any thing special I should look for? General advice for someone new to the FE world?

Thanks in advance for your time and advice and happy new year!!

Mack

S code is the correct code for a big block GT Mustang. A code shows for a 289 and K code was the 289 hipo. The X in the lifter valley of a FE/FT block means it's a HD casting. Reinforced crank saddle and main webbing. Some will swear it means high nickle content which is bunk. The X's have been used by Ford on blocks since the model T days FWIW. A C6ME or C6ME-A 390 casting would be correct for your car I believe. So yea there is some difference between the FE block castings. They all look the same but there are subtle differnences. A good 390 block should run around $100. I've been givin more than my share of 390's by guys who just don't want them. I still see FREE 390's every once in a while. I'd look for a complete engine. Buying piece meal costs much more in the long run. You should find complete 390's for $200 or so needing a rebuild and sold as a good rebuildable core.

G.

If I am right there is also a X code car for 67 and 68 mustangs that is a 390 except it only stands for 2 barrel 390.If you would ever see a Z that stands for a 69 and 70 Boss 429 mustang, you never know there may be one in a barn or field somewhere lol.Dave

hey check in canada dime a dozen i the autowreck

Im it the stage of building one right now i can let u know i a a day or to what it puts out
got a scat crank . head work cam lifter the works no blower
but 11.1 compression it think or it was 12.1 it still in the shop im still learning about 390 my block is 30 over

Other thing to look for is the date code. If memory serves, it's near the mount point for the oil filter adapter. First digit is the year in the 1960s. Letter indicates month - A for January, B for Feb, and so on. Last two digits are day of month. You can get your cars scheduled build date off the dataplate on the door (something like 16D for April 16). Look for a block a bit earlier than that if you want to really fine tune it. Depends on what's available, of course. My April 428CJ car had December head castings. Service block at this point, and I can't remember the date on the original. You can go nuts with this stuff. Intake is the easy one to look at date on. Heads are under valve cover, and block is down low behind stuff. Other than that, check the bore to make sure it's a 390 and not a 352 - most of 'em have 352 on the front of the block.