Ok, have a few seconds.
#1, Tor R is generally correct
There are a number of ways to take this. you can run it like ya stole it, or you can decide to fix it. what level of fix is up to you. I believe that you have an unstable saw as is... in reality, if I was going to purchase that saw, I wouldn't give more than $50 for it because I know whats involved in rebuilding such an item.
So lets look at saw values for a second. In nice shape, a husky 340/345/350 is probably worth about $200-250. ported / nice plastics etc maybe 300-350 max.
If the saw has an issue that necessitates pulling the jug, the value goes down considerably. a husky 350 with a nice p&c might be worth $75-100 .... 340/345 don't have as nice of jugs, so $50 or so is reasonable for saws that need work/ missing parts. So lets work with those values for a bit.
a 346xp has a nicer jug and a metal (mag) case... a 353 (351 isn't in the USA I don't think) has the same jug as the 350 but a mag case... ...I think
Anyway, if you have a 340/345 that needs its intake partition swapped, in many people's eyes it isn't worth it. Odds are you can pick up a saw that has already had the upgrade for pretty cheap, and use the current saw for parts.
Personally, I think upgrading to the better clamp is a great opportunity to learn something on a saw that is going to eat itself eventually anyway. I can't tell you how many saws I've seen that have scored P&C's and that stupid intake clamp is loose. If you want to keep running it as is, please don't count on that saw functioning for much longer. Using good oil will help the margin of error, but eventually, that air leak will win out.
Another way to look at it is the sooner you do the upgrade, the more likely you are to be able to keep that particular jug indefinitely. If you want more power, now is the time to either upgrade, or consider a different saw (ported 350/ 346xp etc)
Where I disagree a little bit w/ Tor is that the plastic cases hold up pretty well. The downside to the plastic chassis saws is that the mufflers can get hot, fall off, and burn through the plastic. but, this is remedied with adding a simple muffler bracket that is not usually on the 340/345 350 series. I think the plastic is actually lighter, and holds up quite well.
Worst case, replace the chassis, if something goes wrong... you can find used chassis on ebay for $40-50 ... its an hour for me to tear these saws down... not a big deal at all. Nuthin wrong w/ tearing things down and cleaning them once in a while.
hope this helps...
