well guys I'm having a tuff time finding a aftermarket block so I have a line on a good 230 400 block sonic checked .226 finished bore at the thinnest ...with aluminum caps what HP level do you think I would be safe(reliable) with N/A??

Maybe 800 to 850 hp. Koffel is the guy to talk to. Those guys basically invented the high power low deck setup 30+ years ago when they started making the B1 head. Their combo was a 400 block with aluminum caps but I think they grouted most of their blocks. They might have pushed those stock blocks past 900 hp but I don't know how long they lasted.

i ran a 400 230 block filled with B1 original heads the cylinder wall got out of round the car slowed .500 i have a 588 B1 pso motor for sale with a koleno block,Bryant crank 55 mm roller cam 945 lift .Cp pistons all the best Parts Built by Best Machine.peterson dry sump Marcella sheet metal sv1 carbs.too much to list. its on Racing junk . i just bought PeteCostas Hemi Pro Stock Motor im looking to sell it .it made 1215 hp it went 7.43 at 2600 lbs thanks John

Ya Johnny I seen that motor wish it was in my price range.....what kinda power where you making when the 400 block started giving you prob?how much run time?did you sonic check?thx for all the input guys I think you right Andy pretty safe at 8-850hp.

Fill the block up to just below the bottom of the water pump holes...will add approx. 15% of strength to the block overall, and help keep the bores from "breathing" so much under WOT. That, and a good tuneup, not over revving the engine will all help it to last a while.

Well, my little 400/512 build has been great at 755hp with no signs of any issues since adopting new valve train....I would go a bunch more if you keep the rpm reasonable and hit the tune up right. Mine is not filled, only has a girdle. I have been contemplating a 383/496 build with an F2 at 18psi....So I might be able to let you know at what point it lets go......

Tom Hemphill in Pa can tell you exactly how far you can push that block. He may even be able to point you in a direction towards an aftermarket block.

ya im thinking this one will make 900+ so I'm alittle concerned......

i had less than 75 runs on it it was filled to the lower water pump hole i never sonic tested it i gues it was making abot 880 it went 7.81 in my Daytona with a clutch and lenco. the cylinder walls got out of round and the car slowed up bigtime. i said to myself no more stock blocks so i built the Pso it only has 34 eighth mile hits and about 6 quarter mile hits

my 400 was a Hemphill motor

B1Johnny- Do they still make the pso heads anymore? Thanks

NO ........ I have a killer set of original B1s for sale in the forsale section.....

when Best had the heads they had to buy 5 sets from Koffel i dont think there is any around. they flow 475

Wow.....475 is a bunch!

I'v just drop the pan on my 400 base -1 heads this morning to fix an bent oil pan,look up inside the lower end of it and BAM.....stress cracks it made right around the 700 hp mark I'm done no more stock blocks for me.

i have a 400 230 block,b-1 originals motor,think its junk,i had better luxk with sr and 440-1 heads,also have a 440 with b-1 heads,cant make either run,if your going to build a 400 stroker,use a later block,same with 440

I run a 530 cast 400/512. It has the center 3 billet mains. I know I am on borrowed time at my power level. Good thing is I have an aftermarket build in the works this winter.

Wookie how many passes so far??

One thing that has me thinking and scratching me head for an answer is my old 500 cubic inch 440source assembly made 275 passes running 8.60’s (440 block build) before it cracked a block. That was back when every track I ran was running 1/4 mile. Now every track I run in “box class” runs 1/8 mile. The only way I can now make a 1/4 mile pass is test n tune nights. I wonder how long that black CJ would have lasted running 1/8 mile only. Hmmmmm. Having a Keith Black block and a mega block I will never find out but I’m still curious.

72 this year. So far so good.