How to install a 454 in a 57 chevy truck?
Any awnsers?  

It isn't any different than puttin' a small block in it. It's just a little tighter around the steering box. If you're going with an automatic trans, the first thing you have to do is remove the stock bellhousing crossmember. Drill the rivets out in the center, starting with a smaller pilot bit then finish up with a 5-16 bit. then take a good sharp chisel, knock the heads off and punch out the rest of the rivet towards the inside of the frame. then take a sawzall or a cut-off wheel on a grinder and cut down thru the center of the crossmember. It should fall right out if you hold your mouth right. A trans crossmember from an early camaro or firebird will fit inside the frame perfect. the total length  measurement on the crossmember should be 33 1/2". You will have 1/8" movement from side to side. Assuming you have already set your clearance between the back of the passenger side cylinder head and the firewall at approx. 1/2", position the crossmember under the trans mount [use the type with two holes on bottom of mount] and bolt to mount, Make sure the crossmember is straight in the frame, mark your frame on the bottom of rails to line up with holes in member.  Again, start with a smaller pilot bit, then step up and finish with a 3/8" bit. Put your four 3/8 x 1" bolts and nuts in holes. You hopefully have figured out by now that if you have the flat panel in your floor over the trans, you will have to replace it with the one that came with the old style granny 4-speed tranny. With the carb off the intake, set a small level on the intake where the carb sits and adjust the height of the engine to where the bobble is in the center. Then turn the level 90 degrees and check side to side level. Your now ready to set up your motor-mounts. That my friend will get you started on the right path. Good Luck!  

Couldn't have put it any better, thanks Smurf!  

Not a problem John! Been there and done it. That's the most straight-forward approach he can go with and get it right.