bradford auto parts starke fl. has a 2000 454 from chevy express van knocks but runs 500 bucks. these L29 are nice engines 904-966-0774

 

82' block is a Mark 4........nothing different from any other 2 bolt Mark 4 block. The 2 bolt is as strong as you will ever need......good to 800+ horsepower. I punch all Mark 4 blocks .060 to make a 468.
A .010/.010 crank is no big deal......really....NO BIG DEAL. Think about .010 radially...it is .005...just thicker than a human hair. Turned cranks being junk is a myth created by the same ******** who created the "high nickle" small block and 4 bolt 400 blocks being junk.....
But if it were me.....punch it .060.....square deck it .020......and buy a Balanced Eagle or Scat rotating assembly.
I have punched Mark 4's to .070 and .100 with a half fill......your .060 will be fine. 468's are as common as 406 small blocks.......
The 496 is cool......but some blocks with shifting require clearance and well built 468 will make 550+ lb/lbs. torque......in a street car.....496's just break **** faster......you will never notice the extra torque a 496 has when the tires are spinning.....
I am doing a GEN 5 right now that is going 468......using a Scat assembly this time around......I thought about using the stock crank but by the time you buy pistons and rods and spin it up to balance.....there is no savings.

Jebby

 

I've never heard of a cast crank being hardened in any way - they're not nitrided, heat or induction treated.
One of my machinists said that the bearing shell thicknesses for .010 and .020 are the same, as are .030 and .040. Thicker bearing/babbit material on the .020 and .040 made it easier for junk to embed in them with less chance of surface damage. This is on a daily driver rebuild type overhaul.
One thing that can help is a generous radius on the filets when it's reground, similar to what aftermarket cranks have. You can only do so much with a .010 or .020 grind, though.
Take that puppy to a machine shop and get an opinion of the bore condition. If you go to .060, make sure it's torque plate honed and the decks are cut square.

 

Lots of good info here,
thanks Derek for the info, I think I’ll be able to make what I have work
Thanks Jebby, good to hear your thoughts on it. My concern was if a ground crank and a 60 bore would still be reliable enough for 500-600hp. I do think that I’ll reuse the crank/rods and get new cast pistons.
this is all provided that the block and crank check out good from the shop.
overall I’m still content with the purchase, not exactly what I thought it was, but should work out alright.

 

DUH...brain fade.....thanks!

 

.010 crank is no issue. To make a good solid bottom end, polish crank and verify all the clearances. Put some good bolts in the rods and install some basic forged pistons to get some compression.

But here's where it can get crazy. First....most folks will tell you to rebuild the rods when you install the new bolts. Good idea. But there will also be a cost to press the rods off and change the pistons. Somewhere along here is where you weigh the cost of getting a basic set of aftermarket rods already setup for floating pins and get forged pistons to match and assemble it yourself. The labor savings of installing bolts/resizing rods and pressing pistons on and off will come real close to a new set of rods with the cost of the rod bolts.

.060" over is no issue either. Changing pistons allows you to select later designs with thinner rings, horizontal gas ports, lighter weight etc.

Figure in some balancing costs to make it all perfect.

Now it gets crazier...because that can get you close to a complete balanced rotating assy for a 496! And it "could" be externally balanced to use your old flywheel and balancer....but internal is better...which will add the cost of those items.

Or real low cost...I'd still bore it .060 and install forged pistons on stock rods with better bolts installed at home carefully!

Ck clearances on mains and rods closely.


JIM