Topic: swingarm compatability? 750f motor mods?

[miles nowhere]

so i just picked up a spare 78 750f with 17k on the motor, and instead of using it for parts i would like to make it really dumb. thats what i like, dumb bikes.
1. I already have a cbr 900rr front end for it, and am trying to figure out if any(and which) "modern" swingarms will fit with a little alteration(Im a competant welder). anybody have any experience with this kind of nonsense? sellers on ebay have proved to be quite unhelpful with measurements and whatnot.
2. I want this motor to go faster and perform better.  Ive heard that the later F models are not nearly as affected by 836 kits....so...what?..im not exactly clear on the procedure and exact function of porting...anybody with 77 78 F experience got a few minutes to send me in the right direction?
3. Im not rich. at all. so spending $10k on a rebuilt race motor is not an option, but i do have patience and a heated shop for the winter..
thanks for any help
miles

[miles nowhere]

....nobody?

[kghost]

Many threads on the F motor Vs the K.

Generally the K is prefered over the F with different valves and combustion chamber/piston

[scondon]

836 pistons and use a late model(77-78)head from a K model bike. 75-76 K and F heads are good too. You will want to either cut a channel in your cylinder block to let the oil flow down all eight return passages of your F2 block or use cylinders from the above mentioned models. Send the head to Mrieck for porting,springs,valve work and pick up a cam from either Megacycle or WebCams. You can put together a decent motor for under $2000.

[MRieck]

Many threads on the F motor Vs the K.

Generally the K is prefered over the F with different valves and combustion chamber/piston

Many, many threads.

[joeb]

I agree with Sean about 2,000 bucks and a head worked over by Mike and you will be pleased. By the way Mike, Sean and I pulled my motor this weekend and replaced  the keepers and retainers with a little help of air pressure and a fancy valve tool and alot of patiance. Thanks Sean and Mike.    

[miles nowhere]

thanks.

[Jerry Rxman Griffin aka MuthaF'er]

A 77/78K head and a 75/76F head will all be easily identifiable by a 392 cast onto the top fin intake side between cylinders 2 & 3. I believe these heads are the same. My K8 head also has K8 hand stamped next to the 392. If you were inclined to use the F2/F3 head (410 cast on it) due to wanting larger valves, I'd still go with the other 392 head and have larger intake valves installed while you are having the head work done. How do you guys feel about this?

From looking up part numbers the differences in these 392 heads appears to be in the valves, retainers and keepers (cotters) with the springs all having the same part numbers. The valves, retainers, and keepers appear to be the same in the 75/76F and 77K while the 78K changed. Mike has extensive knowledge about these heads and would be the guy to talk to and have him do a head for you.

Jerry

[miles nowhere]

thanks for the info, thats the kind of specifics i was looking for, i just couldnt find a way to search for it without sifting through a hundred unrelated pages. A friend of mine had sent me in mikes direction a few weeks ago so i guess everybody thinks hes the man to talk to.
thanks for your time
miles