I wouldn't do any machining til you have all your bottom end pieces so it can be bored,fitting,balanced at once

 

at least bring the block to the machine shop to have them mic the bores and tell you how far they are going to have to cut it. once you know how far they are going you can order the pistons. than bring it all back at once.

you doing a 393? you can get a cash crank from summit for around $400, use the 351 rods and 302 pistons. its pretty cheap considering you will have half of that into the stock crank after its ground, chamfered, & polished. its well worth the extra $200. block clearancing is minimal.

 

yea i would be doing a 393 or 408.

i didn't think the block had to be clearenced when doing a 393

 

add the piston pins,apr rod bolts and balancing is a must!

 

but still why is filling the block half way so bad?

 

HEAT,WIEGHT

 

but if you have the proper cooling system is it still such a bad thing

 

no, but you must keep in mind the 2 main weakness of the block. filling does little to help either of these. the block will split before the breaking point is reached on the lower end of a 351w block. (302 it helps). its main advantage is that it helps keep the cylinder true and alows for more agressive boaring of the cylinders.

1. ford small blocks main caps have a tendincy to walk or move under heavy load. this is mainly because there is only 2 bolts holding each main cap, the other reason the maincaps are quite small. this flexing stresses the main bosses to the point of failure. this is why stud girdles are used, they have little other use. the 351w is generaly stronger in this area then a thin cast metric 302 (5.0).

2. the lifter area on roller 302 and 351w blocks are very thin, this is why newer blocks are a few pounds less then the older (much stronger) blocks. under high power this is where you see the block split, it starts inside and shoots the front and rear traveling downword (just like splitting wood) it ends up cracking below the head to the edge of the waterpump/ front cover area. (or around there)

the newer roller 351w blocks are the weakest of the 351w engines. pre76 aprox were the strongest i believe.

302's are a little different

 

I don't think it's a good idea unless u wanna build somethin and end up with a straight track car.

 

so are you saying i need to find a stronger/ different 351 block?