johnny you can go exactly 1" no problem as far as strut to tire clearance with your size tire. if your wheel is sticking too far out though you may have rubbing there, you gotta see if the tire to fender can take the same 1", the strut can def take it though. after this strut mod you won't be able to mount a stock sized wheel & tire on your fx anymore, a stock 20 will rub on the strut at 1". I could care less personally & don't ever plan to run stock tire sizes anymore anyway, but just so you realize that. I would get a new set of swaybar links & shorten them the same 1" to maintain the same front swaybar position, but pelon & merchant don't seem to have any issuers at 3/4" so may not be that big a deal, don't know if the swaybar has that much extra room to the axle, to keep it perfect I would do thge shortend swaybar links too especially awd
your tire is 1/2" shorter than stock, you can add half this difference to the base 3/4" to see that 1" the lowest you can go with the strut mod.
alan heres the latest monroe master catalog. it's the gas magnum that's labeled as f250 front, think it's 80-86.... there are bilstiens available that fit that application that may be even better?, think the magnums cost me around $85 a pair, bilstiens are $75-$80 each I think... I haven't tried them, if you want to stay on par with your front kyb's then the magnums are a good choice, technically I would think that you should be able to get kyb's own equivelent to your front struts in the correct application for the f250 & it'll work fine too, be like the kyb you have now but shorter & can't bottom out.
I don't say don't do the coilovers because they'll make it higher. as the fx sits with the full stock upper rear spring bushing, if you swap out the upper bushing for a lower seat & install this coilover at the same time the rear height will probably be around the same as it was, the upper bushing swap drops & the coil raises again. end result is a higher spring rate by an estimated 20% or so at about the same ride height I think. my fx is lower with 1 3/4" dropped rear arms, when I swapped the upper seat & the coilover my end result was a little raised than before, but without this extra lower arm mod I think it def won't be slightly higher like mine was, should be around the same... could even be slightly lower? if it was then that's no problem you can adjust it by using a cut upper seat instead to bring it back up a bit
****I say don't do the coilovers with stock front H&R springs, the back will be too firm compared to the front, won't be well balanced
****I think 1/2 coil cut from H&R is alot closer in spring rate to a stock eibach, just 1/4" lower than an eibach. I trust a 1/2 coil cut H&R at least as much as a stock eibach, never seen a cut H&R snap really
****just adding this coilover to an otherwise balanced fx will ruin the balance by making the rear stiffer than the front.
you need to stiffen up the front to be able to do the rear coilovers, you can run eibach front with H&R rear as one solution or
you can run H&R's all around with 1/2 coil cut front, modded strut, added coilover in the rear with the upper seat swap, then it'll be firmer all around & ride even better than stock H&R ride. this is also the lowest combination. this is my recommended best setup at this point. there are no suspension problems at these heights but if your wheels are too agressive & stick out too much then you may rub instead of tucking, if your running spacers you may want need to remove or reduce them...
I have learned alot with swapping these suspension components in & out, but realize that I can't test out each & every configuration, so anyone playing around following any of my advice please realize that I can't control weather your wheels tuck or scrape, that's up to you to judge, & you may have to play around with the rear to get the rear ride height just right.
