I'm sure there are people on here that has done this conversion, could someone please direct me to a thread or give me some direct advice on the things I need to know, like where to cut and what to cut

http://www.moparts.org/Tech/Archive/auto/28.html Lot's of pics, the clearancing is overkill IMNSHO, but it's a sound install and will avoid drive shaft angularity issues.

The best advice I can give you is to use a GM200R4 from Extreme Automatics instead. They consume a significantly less amount of your precious HP, and are substantially smaller = no floor cutting. You will need to use the US Cartool kit to make the torsion bar cross member cut, which you will be doing anyway. Besides, they are much stronger and have better gear ratios.

Or, put that old, patched 727 w/OD added on the back A.K.A 518 in it, and hack your floor too.

I used the A500 in my '69 Valiant behind the 408, the tunnel itself did not have to be cut, the section of the crossmember that went up and over the trans, had to be removed, and we made a flatter version in it's place. Of course the trans mount/crossmember had to be custom made.
I don't plan on racing it much, if at all, so the A500 should hold up, I had Darren at ProTrans build it.

I put a 518 in my Rampage but its not gonna help you.. I have a tube
chassis in it but the tunnel is close to the trans and the shield

I have an A518 in my '73 Dart.
Top side of the crossmember needs to be removed and rebuilt/replaced with either a thick plate or on the inside of the cabin. (If you don't replace the crossmember top, the crossmember left&right will start to tear loose from the floorboards. Ask me how I know...

Lower crossmember can be modified to accept the A518 mount. A mid '80s GM mounts works nicely.
On the left and right side of the transmission tailhousing I trimmed the strengthening ribs for clearance.
I 'massaged' the tunnel near the OD-flange to the transmission body to make the transmission sit at a good/better angle. Otherwise the (stock) deep oilpan will sit lower and driveline angle is worse.

I have some pics on my website but not really the mods needed to the transmission or tunnel.

I installed a 518 behind my 6.4 Hemi. Reverse manual with trans brake and lock up torque converter.