I got probably one of the first Harken rollers on j30 for #327 back in 1982, subsequently moved that to #505 in 1985 ... and now in process of changing that to a Harken IV Series 1.

the first thing to resolve is the forestay length. and I am having a bit of difficulty translating this site's info.

What I have on the floor now is 35'9" from inside pin to inside pin with max turnbuckle length. That's probably 35'10 to centers of pins.

then what length is the OD measurer going to check once it is installed.

Sorry to say I did not pay better attention when we were measured in Marblehead. Does pin to pin mean dead center of pin? I don't remember any comments about "Sheer Line"

http://j30.us/blog/?page_id=322
Forestay 35 ft; 8 in.; 1/4 in.;
Marine Eye to Turnbuckle - Max. Head stay length is 35'10 1/2 in.; measured to the Sheer Line at the bow stem fitting.(rule 5.8.2.1). The measurement listed is pin-to-pin of the stay.

If we take 3 inches off for socking the turnbuckle up that would give me a shortest length of 35' 6" inside pin to inside pin. Use of the word "turnbuckle" also confuses me as that is an adjustable piece of gear.

35'-10 1/2" from centerline of pin at hounds to the sheer line at the bow.

From the tuning guide on j30.us: http://j30.org/html/rules_clip_image004.gif

Today measured from "measurement point" [figure 1 above] to center pin on stemhead ... pretty close to 2.5 inches. The new forestay is 35' 9" ~maxed out at turnbuckle [center pin to center pin].

With the sheer line 2.5 in. to center pin, it looks like we have this covered. Will measure, as recommended, to the top edge of the swage on the turnbuckle and store that number as the base line.

Always good to know how long things are before we send someone up the mast. I have no idea how long the original unit is as we never measured it since 1985 when it came off #327.

Ok ... update.
forestay from pin to pin centers with turnbuckle showing ~3/4 in. of treads ... 35' 8 in.

Plus Sheer line to center hole on stemhead 2.5 in.

Total length 35 ft 10.5 inches. and that is apparently max. which is apparently where we want to be.

I don't think we can take this measurement stuff much further.

There is another thread that was the basis of NA measurement up in Marblehead that seemed to work pretty well with just running a steel tape up on the jib halyard. And perhaps someone can tell us what that technique is.