How much HP thru a stock 351 block

[sofakinfast]

Just thought I asked for everyones opinion on how much HP a stock 351 block can handle before comming a time bomb. Take into consideration that the block in question does an ARP main girdle and has been preped with Hard Blok. Don't know if that really helps or not. It seems that with evryone you ask you receive a different answer.

Thanxs
Ian

[1slo5.0]

Mike James is pushing damn near 1000 hp thru his 351 block. A main girdle will help keep the main caps in check but you should really dowel the caps to help prevent cap walk if you plan on making any kind of horsepower with it. Also, if you use hard blok make sure you have the block cleaned first and use the Hard Blok BEFORE you have the block machined.

[dave bandt]

Yeah....the James Gang will tell you where the weak area is. Cap walk is an issue but the lack of meat in the main webbing is probably just as important. 1000 HP with a good tune has been done plenty of times....but it will eventually fail. There are a lot of things to consider....but RPM, power adder, tune up, and HP level are probably the biggest. I'd say if you want to make over 700 RELIABLY save for a 4 bolt block.

[BBATCO1]

Girdles are good for keeping the crank in one piece when it does blow. Hardblock will only help strengthen the cylinders. Which are paper thin on a late model block anyway. I have had a stock block 302 based at its limit for years, I used to cross my fingers everytime I sprayed it. I will say that attention to detail during the machining process will greaten your chances quite a bit. The less weight you swing on the ends of the crank the better.....

[Blowngt92]

Early 351 blocks seem to be the key. My new motor is a 74 fully prepped block. I have been told not to waste my money on a girdle. The early blocks had better webbing and more nickel content. I will be pushing 20lbs boost through it, i guess we will see how it turns out.

[drag79stang]

I ran that stock 2 bolt main block (out of an 84 squad car), for 4 years. No problems. Never had any breakage, (other than the crank this year, but that was AFTER engine came apart).....kinda.
People I'd talked to said anything over 600 hp thru a late model block was pushing it.
My thoughts are if the machining is good, and everything working right, it should last a fairly long time.

I did however step up to a 4 bolt dart block this year, (just to cover my butt)...........

[sofakinfast]

Dragstang what all did you have done to your block?

Does that hard Blok make that big of a difference?

[dave bandt]

Dragstang what all did you have done to your block?

Does that hard Blok make that big of a difference?

The weak spot is the webbing in the mains not the cylinder walls. Hard blocking will help with cylinder wall stability but won't do anything for strengthening the bottom end.....where it needs it.

[drag79stang]

Only real neat thing (done to block), was I tapped/plugged the frost plug holes with the screw in plugs. THAT , plus excellent machine work, kept mine in one piece.

(that and maybe lucky?)

Didn't use any hardblok. Heard too many stories about overheating issues. (I ran plenty warm enough as it was). Good luck. have fun.

[sofakinfast]

thanks guys