390 short block ????

[fekbmax]

I'm a fan of the main stud girdle. Have used 3. One on a 390 based block with cut down factory caps. Its still going strong in a well used and abused f250 4X4. Still cringe a bit when thinking about cutting down the factory cast caps but its still going strong.
Second build was a 105 mirror 3 web block with a full set of program 2 bolt caps. Expensive  for sure but i felt much better cutting those caps down. Its at .040 over with a 3.98 stroke steel crank with ford size rod and mains. Still running strong in a 3000lb 69 coup mustang , crash boxed drag car.
Then my currant A scratch block build with cross bolt program mains.
There is definitely some extra machine work to be done but personally i feel any high performance build should have all the surfaces square decked off the mains including the oil pan rails, bellhousing,  water pump and timing cover surfaces.  JMO. Of course you need to do your align boring with all your hardware and girdle in place. Be sure all your block filling is done before any of the machining.

[jayb]

There was an article about Ed Pink's SOHC engines back in the day posted here a few weeks ago, which showed them using a 1" thick block girdle on a 427 sideoiler block, to make the block live (for a while at least) in blown fuel applications.  To me that says a lot.  For sure, a girdle can only help, especially on a non-crossbolted block.

[FERoadster]

I was going to post earlier today about my 390 block that cracked in the main saddle.
Just a stock 1973 390 2bbl PU. Driving back from Wyoming on the expressway @ the then 55MPH speed limit I lost almost all oil pressure in eastern Nebraska. Put a mechanical oil pressure gague in and made it back to SE Michigan with about 15 # oil pressure. Needless to say I scrapped the block. It doesn't need alot of HP to do this.

Richard

[66FAIRLANE]

Now I you have me worried about my 390 block. I drilled all the oil passages to 5/16 from the saddle to the cam bores. I am hoping to make a power upgrade to near 500hp soon. If a block does crack there does it just loose oil pressure or can it cause catastrophic failure? I would hate to throw away a fully prepped/machined block because of it. I never turn it over 6300-6400rpm. Jim

I suppose like everything it depends. When I rebuilt my 390 it looked like someone had enlarged the passages but only part way down to the cam bore. Not liking this I made a longer drill bit and opened them up all the way through to the top oil passage. It wasn't much and can't remember what size, I will have to dig out the drill bit and check. This was all done 20+ years ago before I knew any better. Saddles were modified to the bearings also. Not a race car & softened with an auto & converter but this engine sees 6000rpm numerous times every time I drive it, has gone to 6500 countless times and even ventured to 7K on a few occasions. Hasn't broke yet....... I suppose now I have said that my days are numbered!

[steinauge]

Just curious-is there any way that S O block could be repaired for non racing use? Reason I am asking is I have repaired some very broken early HD cases succesfully just because there were no spares.