[Krusekontrol]

Just a suggestion,

Although you can fit the 350 on the stock swingarm you will improve the ride if you balance the increase in length at the front of the main frame and a little bit in the rear.

You can do this by cutting out the center bar on the bottom of your swing arm. Cut it in half.

Make your next cut just past the bearing housing plate and insert the 2 new pieces. after you weld it lay some angle iron across the length to spread the load across the base.

Now the bar you cut away will be replaced with the new metal in the proper position for your engine mount. For some engines like the 350 you can mount it sideways to eliminate the exhaust problem. However with the extentions you will have plenty of room and a very smooth ride and reduced bounce in the rear when your hitting jumps.