twin turbo 305?

I want to build a twin turbo 305, but chevy doesnt make a 4 bolt main 305. i have heard of a kit that you can convert a 2 bolt to a 4 bolt, but i do not know how reliable it would be. the kit uses the existing main caps. you drill and tap a place for 2 more bolts on the outside of the existing bolts. they are angled inword.
 
has anyone else heard about this kit?  Is it reliable?
 
If  it is no good i will just use a 4 bolt 350.
 
any input is usefull!!
 
thanks

it would make more sense just to use a 350

I personally have never herd of this but i would use a 350 u already will start with more power than a 305?

converting a 2 bolt into a 4 bolt is called splaying.  But it is very expensive at the machine shop, the only advantage is that they said it is stronger then a 4 bolt but not cost effective unless your building the best of the best .

i would just start out with a 350 cuz there isnt that many aftermarket parts for the 305's. plus you start out with more hp with a 350

For a twin turbo engine I wouldnt use a factory block for the expense you would go through whats an extra $2000....  you need different caps and line boring/honing when you splay a block it is stronger than a conventional 4 bolt in our area the job will run around $800. The registers need machined also. The aftermarket block is already splayed add in the machining of your used block and it would be close to a wash .....