.60 over or new block??

p.exeter_bleu

Founding Member
Jan 6, 2002
293
0
16
El Paso,TX
ok so its a possibility my rings on my 351w are done for right now it sits at .040 over, an overhaul would put me at .060 over. should i go .060 over or just start with a new block at .030-.040 over again? will the .060over block hold up i plan to run forged pistons, and most likely its gonna be an N/A motor, but maybe sometime down the line i would like to go with some sort of boost. would the .060 over motor be able to handle boost? or should i just start with a new block?
 
Tough call to make. You can go to .060 over, but that does leave you with no more material to remove at all if anything goes awry. You could also sleeve the block, but you'd probably be in the price range of a new block + machine work for the price of just having the current block sleeved and machined. If it were my decision to make, I'd probably be searching for a late model 351 roller block and start fresh. I may even stay with a standard bore just for reasons like this.
 
the overhaul with going .060 over would cost me around 1750.00 according to the machine shop(more for forged pistons) that includes fluids and pulling and dropping in the motor.

i have seen some 408 shortblocks on ebay for 2,500 could i use my 205cc pro topline heads and trickflow 351w efi intake with this motor or would i be choking the 408? my exhaust is 1 3/4" longtubes into 3in exhaust. anyone have anything good to say about these dynoflo shortblocks on ebay?
 
it all depends on the block. the only real way to tell is have your machine shop ultrasonic inspect the block to determine wall thickness. But at that point you might just want to buy a new block then.
 
if i buy a stroker kit off ebay for the 408 i would just need a new block to complete the motor right? i can get the block machined/cleaned up, install the rotating assembly and probably be under 2 grand right? oh and what is a good year to look for in a block? and what vehicles came equipped with them? i assume i would also need a cam?
 
Are you sure it cannot stay .040? I bought a .030 block and it needed a light hone and stayed at that size. The price seems high compared to what a diy price would be.

i was wondering this myself? the machine shop didnt even think of it as a possibility. at this point i am really leaning towards just building myself a 408. over the winter and if the damage on this motor isnt too bad(requiring .060) i could get it cleaned up and sell the shortblock.

we should see a help me build my 408 thread in the near future with shopping list and such. im gonna go to the junkyards and see what blocks i can find and maybe even see if the machine shop has a block i can use.
 
As long as the block is thick enough (sonic check it) going .060" is no problem at all...

If your bores are in good shape and the walls just got glazed over you can rehone the block which will increase the PTW clearance (piston to wall) but you could re-use the block. Most forged piston set-ups run .0025"PTW going .0035-.004" will not hurt and that is actually where I set them when boost is added, higher depending on the exact conditions.

PUNSIHER is right with the NMRA P/S stuff I go right to .060 to get the most out of the rules, although I have hardblocked a few up to the water jackets for extra cylinder stability.