I have found a site which sells 1250 bore kits for around $800 us. nrhs-high performance.

Yes, have seen their kits they look pretty good. NRHS have a pretty good reputation as well from what I've read. With the 1250 you'd definatley need head work also.

I can't say I'm an expert on them but there's plenty of guys on XLForum that think they are great.

I'm personally going for the Ted's v-twin upgrade around $580 delivered.

try GMR , a site sponcer and theres a few of us here will vouch for STEVE @ GMR  some have spent over $10 big ones with no problems

GO THE 88"    www.gmrperformance.com/GMRPerformance_Sportster_Products.htm

 

Looking to wake up your 883?? or maybe take your 1200 up a notch?? Well how about a bolt on 1250 kit?? These kits will offer more tq/hp with no other mod's add a set of cam s and some head work?? and hang on as these kits will make big power . Offered with different compression rations, stock HD heads or thunderstorm. Give us a call for your sportster needs. See your 1250 dyno sheets as well.

Want more power than a 1250 kit?? how about a 88 inch kit

With the use of a larger cylinder ( case boring required) take the bore to 3 13/16 you can own a 88 inch sportster see the 88 sportster section of dyno sheet as well with 10.5 compression and forged pistons, A build like this need a great flowing head, cams, roller rockers, and of course a great exhaust system.

Good point Mick, I've had a look at that page before, don't know whether I want to go that big, ie 1250 but definately worth a few enquiries to GMR on pricing and options etc.