ive been talking to people about taking the manifold of an lt1 and put it on my l98 but some one told me that it would be better to put the whole motor in...i can get a lt1 out of an impala for 600 dollars .....should i do it?

 

Yes and no, The LT1 will require a new harness that you can get from painless wiring but I heard it takes a few hours to do. If you want a/c youd have to notch the driver side cross member for it to fit. The advantages are its a much stronger motor and you can get more outta the LT1 then a TPI setup.
Just doing the manifold swap would increase the RPMs of the l98 but the l98 doesnt have that great of a head to flow and the rods arent as strong, so its a caution if you plan to make some power. Depends on what you wanna do. Is it gonna be a street car or a daily driver? The cheapest and easiest is to go carb, less wiring and if your good you can tune the carb to make just as much power. Up to you.

 

it is gonna be a daily driver/fun street car but the reason i considered a motor swap is because my friend has an lt1 sitting in his garage with all the accessory's for it.

 

Well if you can get the LT1 do it, but look foward to hours to splice the harness in.