OldCarBum

I picked up a bare, 454, 4 bolt main block to build for my 73.
I ran the casting number, 10069286, and found it was manufactured as a 1990, Mark IV, short deck, 454, 4 bolt block.
Will all the parts I've been collecting for a 73 Mark IV interchange with this later 1990 Mark IV block?

bjankuski

Yes

L88Plus

Other than tall decks, that's the only Mark IV block that was only fitted with 4-bolt caps. All others can be either 2 or 4 bolt.

derekderek

With some reading, it looks like this 286 was the last mark 4 454 block. And they started with the thin wall castings that they went with in the Gen. 5. So might be a good idea to sonic test this block and make sure everything is on center. Also look closely were the water pump bolts to the block for salt water corrosion eating the block thinner right there. A lot of these engines were also used in boats I believe.

OldCarBum

The machine/speed shop I've been working with tested and checked everything on the block before I purchased it from them.
Thanks.

ronarndt

Keep us posted on the progress building your big block. I have the top end on mine in my 68 convert modified where I want it, am going to change out the rods and pistons next. Fortunately there are loads of add-on goodies available for the 454.

OldCarBum

I will be starting a body off resto mod later this year and I'm stroking the 454 to 496 and swapping out the TH400 to a TKO600RR plus many other goodies.