A wee guide and lots of choices , valve seat work is the key, Wassers respond well to valve sinking, the downside is it costs compression pressure, first off, they are tight on installed valve spring height, roughly 1.4", the performance way to a win win fix is to sink the valve .080", I won't go onto a porting and seat flow waffle, but it's the key to big gains from seat profiling for out and out motors, sinking also fixes the spring height problem back to a workable T1 spec enabling T1 hardware and geometry to work, it also gains piston to valve clearance, but all the chamber matching and profiling costs a deal of compression, it just costs cash to gain it back, another story,, A compromise is to cut the spring seats or use a higher spring height retainer such as bergs 281A, these gain .150" spring installed height.
Conversion valve guides are available for the exhausts at 8mm stem, but again, light stainless valves cost compression as they are dish heads, mine are made by Paul Ivey and trim off stock 20 odd grams tho much bigger, but the stockers can still flow 170hp ,but need some valve spring pressure to go over 6000 rpm. I use 175 lb installed and 285 nose for 7000rpm with stock jobs. One thing is the Febi lifters are heavy and need shorter push rods, a solid conversion on stock hydros is my way if you don't need a T1 lifter conversion, lighter than solid T4 and better oiling, and the stock length steel p/rods can stay, they are fine at 6000 rpm.
Very interesting.
The spring height is going to be an issue I suspect as the cam/lifter combo will be just shy of .500".
TBH I specifically selected the combo as I wanted to avoid further complications with clearances.
Regarding valve sinking, this clearly gives me big headaches as you say, so I would rather avoid it if possible.
I'm awaiting Jim's verdict on the heads and will decide then.
I like the look of the berg retainers plus i'm keen to lose some unnecessary weight here.
Thanks for the heads up on Paul Ivey, I will pass that along but if I can make stocker's work and retain the compression ratio I feel this would be more suitable for my goal.
The issue I have had with stock valves is tip damage due to repeated hydro bleed downs, but this will be resolved using solids.
James offers some HD aluminum push rods that will expand and keep the valve train quiet when hot unlike the stock steel ones will.
Converting the hydro lifters has been mentioned on this site, probably by bbb and as I have a set of new ones perhaps this is something to investigate.
Thanks again bbb.