lower gearing for a cranbrook

I am building a cranbrook and need some lower gearing because I will be pulling a kiddie trailer. Its geared a bit to high for start off. I have a 36 tooth front sprocket so I think my solution will be something with the rear coaster brake gear. Does anyone make a higher tooth count gear that will replace the stock one? I've looked on ebay and on Jenson's site and cant seem to find what I'm looking for. Any help would be appreciated!

Good news! Thanks for the info! I'll hit up my local bike guy and see what he might have in the bone yard and search for "cog/sprocket" on ebay.
I got it running today and find that I really dont use the coaster brake, partly because I havent used one in over 30yrs-used to linear pull, but if the larger sprocket helps all the better! Thanks again Bairdco!

Thanks for the comment Kip! I've hooked up the trailer and as it sits now the exhausts point under it and are fairly close to it so I dont think I'll have an issue with the exhaust in my daughters face. On my red and black cruiser with a similar exhaust (single) I put a copper elbow fitting on and pointed it straight down. Next trip to the hardware store I'll see what I can find in maybe a 45. Easy to braze on so why not!

I got the expansion chamber from ebay- its for a pocket bike. Unfortunatley I havent found them on ebay for the same price! I only paid 10 bucks for it and another one thats on my sons bike. The rest of the pipe is just 3/4 in emt which is the perfect size to weld up to the stock head pipe and muffler. I now have a 3/4 conduit bender to make the bends much easier so I might redo this bikes exhaust and try to get the expansion chamber closer to the head to get more power out of it . Needs to be about 10 -12in from exhaust port for best performance, the one on my sons bike is mounted in the up position and his bike flys! Just as fast as my mountain bike with sbp pipe and shift kit and cns carb- at least until absoulte top speed where the shift kit comes into play but thats not until 32mph where his bike tops out. I've been tinkering on another exhaust and bike you can see in the stretch cruiser forum under "my first stretch". All my personal bikes get a custom pipe of some kind- the stock pipe is just so boring!