If you already have the G-body big block headers and a cross-member for a TH400....
For the LS route, grab a 6.0 (around here they are $1800 complete with stock harness, transmission and accessories) Hooker LS G-body engine mounts are $130. The oil pan is $360. The transmission cross-member is $250. The headers for an LS are around $700. Now, that is all before you buy a 6.0 or a cam, or whatever harness and whatever flash or tune. I have seen harnesses go for $350-500. Usually $150 up for a flash or a tune...even if its just turning off the VATS and cats. You will also require a fuel system to support the fuel injection, like a big pump and some lines, maybe a Corvette filter. LS engines make some awesome power, but, if you don't change anything, its going to sound just it did in the truck(stock). If you use the Hooker mounts, oil pan, cross-member, & headers, truck intake manifold and accessories will clear. Column shift linkage will not. Need adapter hoses or a different radiator. Will need another throttle cable. It will have overdrive if you use the whole set-up. If not, figure in an adapter flex plate and pilot hub for the TH400 torque converter (since you have the cross-member already).
For the big block route, get a 454 (around here, right now on craigslist, there are a few for $800-1000 with TH400 with all the accessories) from just about anything ever made. Add a $45 Chevelle oil pan and $15 pickup tube. The 454 will sit in the car with car/small block engine mount cups/clam-shells, they are around $20 each new. Most 454's will have a TH400 behind them. It will fit. It will run. Now, that being said, it will sound just like it did in the dually or truck(stock). The accessories for the 454 will fit in the G-body, the starter, flex plate, all of it and will clear with the Hooker headers you have. Use V8 Monte radiator hoses. The mechanical fuel pump is in the same spot as the 305, so stock fuel lines will work. I have been using Dodge Intrepid fans ($40 used from salvage, $90 new on rockauto.com) and either a stock replacement V8 radiator or a Champion($155 new) all aluminum. Big block style front springs are $60. No flash, no tune. The HEI distributor from a small block or that comes with the 454 will fit and work, you will need to cut the boot down on one wire where the window wiper transmission swings with an HEI.
About all that is left is the drive shaft and it would have to be cut to length in either case.
That is just to either to run. Now, both have some options to make more power or alter the budget along the way.
For the LS route, grab a 6.0 (around here they are $1800 complete with stock harness, transmission and accessories) Hooker LS G-body engine mounts are $130. The oil pan is $360. The transmission cross-member is $250. The headers for an LS are around $700. Now, that is all before you buy a 6.0 or a cam, or whatever harness and whatever flash or tune. I have seen harnesses go for $350-500. Usually $150 up for a flash or a tune...even if its just turning off the VATS and cats. You will also require a fuel system to support the fuel injection, like a big pump and some lines, maybe a Corvette filter. LS engines make some awesome power, but, if you don't change anything, its going to sound just it did in the truck(stock). If you use the Hooker mounts, oil pan, cross-member, & headers, truck intake manifold and accessories will clear. Column shift linkage will not. Need adapter hoses or a different radiator. Will need another throttle cable. It will have overdrive if you use the whole set-up. If not, figure in an adapter flex plate and pilot hub for the TH400 torque converter (since you have the cross-member already).
For the big block route, get a 454 (around here, right now on craigslist, there are a few for $800-1000 with TH400 with all the accessories) from just about anything ever made. Add a $45 Chevelle oil pan and $15 pickup tube. The 454 will sit in the car with car/small block engine mount cups/clam-shells, they are around $20 each new. Most 454's will have a TH400 behind them. It will fit. It will run. Now, that being said, it will sound just like it did in the dually or truck(stock). The accessories for the 454 will fit in the G-body, the starter, flex plate, all of it and will clear with the Hooker headers you have. Use V8 Monte radiator hoses. The mechanical fuel pump is in the same spot as the 305, so stock fuel lines will work. I have been using Dodge Intrepid fans ($40 used from salvage, $90 new on rockauto.com) and either a stock replacement V8 radiator or a Champion($155 new) all aluminum. Big block style front springs are $60. No flash, no tune. The HEI distributor from a small block or that comes with the 454 will fit and work, you will need to cut the boot down on one wire where the window wiper transmission swings with an HEI.
About all that is left is the drive shaft and it would have to be cut to length in either case.
That is just to either to run. Now, both have some options to make more power or alter the budget along the way.
