Here is a picture of a Homelite "twister" manifold, modified for a larger carb. You fill in the areas around the throat with JB Weld or similar, then enlarge to match the carb throat. You also enlarge/bevel/smooth the intake port to match, but do not remove the little "nub" in the top of the port as this is to keep the ring from catching in the port at BDC. Once you modify the manifold like this, you have to set the carb up for external pulse to operate the fuel pump. Note that I do not recommend trying to drill out the manifold, as the large drill bit can easily "catch" in the relatively soft material of the manifold, and break it or tear it up. I use a drum sander in my Dremel to enlarge them. It goes fast...

Here are a couple of links that might interest you with lots of Homelite info:

http://www.rcuniverse.com/forum/m_26...tm.htm#2621860

http://www.rcuniverse.com/forum/m_23..._1/key_/tm.htm (Refer to post # 39 in this thread)

The third pic is of a Homelite with the external pulse setup on the carb, but that particular installation does not have the "twister" manifold. It has the normal one, but also modified as shown. Man, it took me an hour searching through all the pics on my computer for these pics....

Have fun,
AV8TOR