her goes, I have found an FE block that has in the cast 66 427, but when I checked it with a digital caliper it reads 4.080, now thats .030 over the 360, 390 standard correct? so can this block be bored to 4.230 427 standard? argg!! all these differnt sizes and things ford did is driving me to drink, I also have my eye on an ol school bus that I think is the FT 361 or 391, it has the FT, heavy exhaust manifolds, and external ribs on ONE side of the block, morror image 105 on the front no date code and no other cast #'s, lol miller time!! Thanks for any help, Warren

 

Some blocks were cast with the 66-427 on the back but are only good as a 390 (i have one) the outside of the block and the cylinder walls were cast with different molds and as the original molds wore out they would use what ever out side mold was still in good shape and it would have nothing to do with wall thickness. There is a wall gap method where you stick drill bits through the freeze plug hole to check the distance between the cylinder wall but I can't remember the sizes, you can also have the block sonic checked at a machine shop. Does this block have the side oiler nubs inside the bellhousing pattern? If so do they run all the way down the block or only appear in the bellhousing patter? Pics would be great.
-Johnboy

 

Safe bet...
If it's a 390 block, stay with 390 based bore sizes

The benefit of 4.130 428 standard bore over a 390 +.050 (4.100) is "nothing", but you'll have either talen the block to it's limit - - or killed it.

None of the other FE blocks can go to the 427 4.233 bore size.

There may be cases that break the above rules - but I have never seen one and I've been running FEs since 1975....

 

Having the block "sonic tested" will tell you if you can overbore it past the .060 over the 4.05". I had a 1962 390 Hi-Po (375hp 4V) block that went .080 over to let me make a 406, so there are blocks out there that can.

 

If thats a 391 it will also have a steel crank.

 

Yeah, but it will have a snout on it larger than will fit in an FE block.

 

don't the FT engines have the small crank like the 330I know the balancer and pully's don't like the normal size.

 

The mirror image 105 doesnt make it an FT block its a later year casting for the 360 version after 73 for trucks they usally have the extra web supports at the mains and a heavier casting they have been known to be bored as a 428 with some meat left,,, sonic the block will give you the knowledge if it can be bored out more than 0.60,,,as a rule if you bore a block you want to have at lease 0.90+ left in the cylinder walls for it to live awhile. FT blocks were built durning the earlier years of the FE production for big trucks F-600 etc. they are a low compression model with steel cranks as stated but were made as a work horse not a performance motor. While the crank snout was larger it can be millled down to the FE motor but is a very $$ venture and I've yet to hear of the standard FE cranks breaking from beating on or in performance applications motors, and the FT blocks if used need the distributor hole sized down with a bushing to use an FE or aftermarket dizzy plus I belive the exhaust crossover is different as well as the water passage for the intake so you wont be able to use the heads and the heads have -0- value for performance,, there are other things about the FT block that makes it near impossible to be for a performance application. If you have a 105 block that is worth looking into for a build up

 

10 mins on any old lathe will fix that.
Ever wonder where all those 427 steel cranks at the swap meets come from?
There always seem to many,many more of them than 427s were ever made.

 

Besides the lathe work you need to recut the keyway as it will disappear from the turndown work,,that is alittle more involved than spining the snout.