[InitialBoss]

Ok, guys. I'm looking for opinions. I have my 250 inline 6 which now after getting the fuel line replaced from a steel line to a rubber fuel line, runs like crap. It's real shaky and has no power to move forward or reverse after it starts. It will eventually start to be able to move after it warms up but right out the gate, it's terrible. I don't know what was done to it by the mechanic but it wasn't running that bad prior. I don't want to take it back to him because I don't think he is too familiar with our type of trucks. I'm not sure if it's bad gas. It's been back firing sort of from the carb now too. Basically I shut it off and it still stutters and runs a little bit and then poof, dies out and smoke comes out of the air cleaner area and snorkel area.

I'm not sure if I should swap out the engine for a 350 sbc and get my trans sorted out as it's leaking a little bit. Or try to go with an LS swap. The only downer besides the money for an LS swap is that my truck is a '78 and has to have all the stupid CA smog stuff done to it so it's still smog legal. Do any CA guys who have a newer than '75 (I think that is the last year it can be smog free) LS swapped truck have any recommendations on SoCal smoggers? I want to go the most economic route and I know the LS isn't. But I figure maybe it might be worth while to spend the money on an LS swap for power and mpg and reliability than go SBC and low mileage. I can't do the swap myself as I don't consider myself that tech savvy enough to do it and it will take forever if I try to learn it myself. What would you guys do in my situation?

Would you:

A) Just check out what's going on with the I6 and rebuild if needed? (cheapest option I think)
B)Do a newish SBC swap
C) Go for the LS swap and build it up over some time since it's expensive. I do want to take my truck out to get stuff from the home improvement store or furniture runs if needed though, so it can't be down for too long.

I wish I was taught general truck repairs when I was younger and I'm trying to learn as much as I can now but with 2 kids and having family time, it's a little difficult.