Looking to find out how reliable a casting # 511 400 small block 4 bolt main block is . Have heard they are prone to cracking under high horsepower / high rpm usage . Currently have a short block with stock main caps & aftermarket studs . Also has head studs . Has 5.7 " pink " 350 rods with trw 12.5 ( at 64 cc heads ) pistons . Also has stock cast crank ( weak link ? ) Plans are pro action heads , large solid roller , dart intake & 1050 dominator . Also will have 3500-4500 stall & 4:30 gear . Car is a 70 stock bodied nova - for now . Will i be building a ticking time bomb or should i chuck the whole thing & get a big block :D ? Let me know how far off base i am !

mines been living a good life so for for over four years now just keep the rpms under 6500.that motor should run some good times also.i would think the weak link would be in the pistons as for as weight gos spend just a little more and get weisko pistons. the weight savings will be well worth the money for a race motor.this is only my appintion

Not a real fan of 400 4 bolts. They like to crack in the main webs where the outer bolts are.
It sounds like you are planning some RPM (cam, compression, carb) so I would not use the stock crank. They are quite strong up ot about 6000-6500 even at the 450-500 hp range but do not like RPM.
Use a 2 bolt with studs or better splayed center caps if you are going to be making any serious power.
I have 3 - 400 blocks that recently went to the scrap yard with ugly lower ends.
Two are 4 bolts with cracks that I don't know the history of except they were circle track engines & one is a 2 bolt with stock caps that looks like someone tried to weld the caps together they are so fretted.
It was a stockmain bolt 530 horse 7400 RPM alcohol circle track engine with only 3 races on it.
His new engine has splayed caps :D

My stock crank and rod 406 made it through 3 years of racing and was in the mid 10s when i sold it. But if you have the money for a BB, i would go for it.

With the roller cam...it sounds as if you plan on turning some big rpms...the TRW slugs are real heavy..The stock 5.7 rods will have cam clearance problems(maybe) You can buy a new eagle 4340 crank for 369 delivered(I just bought one) it internally balanced easy with 6" eagle H beam rods (305.00) I went with the protopline 50cc heads and flat top wisecos..for 13-1C/R...with out completely redoing the bottom end...keep it under 6500 rpm..and NO N20

That what i thought . Sounds like some of you have had good luck with your 406 but from the looks of it , i would hate to invest that much money in a motor that may or may not survive :mad: . I don't have any real money invested in this short block , got it with another car that i sold & has never been fired . Just thought i could put it to good use :D . Possible good daily driver with 72 cc heads & smaller hydraulic roller . Not what i am looking for ! Now the next question . Small cubic inch big block ( 496 is considered small any more isn't it ? ) with same basic set up , splayed caps , low compression , AFR or brodix heads , large roller , dart intake , 1050 dominator & f-1 or f-2 procharger ? If one is going to dream one must dream in excess , don't you think ? graemlins/hurray.gif What are the pro's & con's of this hand grenade ? Let's hear it !