I heard somewhere that you can change a 2 bolt main to a 4 bolt main with only new caps, some drilling, a tapping. is this true? if so are there any sites that describe the process.

 

im not sure but i dont think it would work

 

http://www.arp-bolts.com/media/pdf_f...9-31_36-37.pdf

 

Its a little more involved than that; but yes.

4 bolt and 2 bolt 351c blocks are the same block one just had more holes drilled in it at the factory.
You will need take it to a machine shop though and aling hone the new caps to the block to make sure that everything fits proprerly other wise you run the risk of destroying your crank.

 

yes thats right you can . but with 4 bolt caps . the 2 bolt caps MUST NOT be drilled out for 4 bolt orperation bad I dear makes them weaker ....

I got a book hear and it has this topic covered hear is a quote from Jack Rouush

" Virtually aney 351C can be a prfromer since thare is no diffrence in meaterials or strenght . In fact, the two bolt main block cap is just as good as the 4 bolt main block eaven the caps are equivalentin strenght . So unless you have a 4 bolt main block don't spend the extra bucks for this feature " Jack Roush

S-A design
Ford Performance
By Pat Ganahl
this quote is on page 75

But if you want to do it , the thread is 3/8 16

 

ok now that i know that it can be done, is tehre a deffinate advantage to be gained form spending the money to do it. i am wanting about 400-500 rwhp and i heard the the 2 bolt block cant hold as much power, which i know akes sense, but any wayu is it worth it??

 

While the 351C was a great motor because they breathe so well but the bottom end was less durable than the 351W. A 4 bolt conversion would be a good idea but you MUST use 4 bolt caps and align hone or you WILL destroy the crank. As previously mentioned, drilling the two bolt caps will also not work because they don't have enough material in them and will weakened to the point where failure is garanteed.