OMC Stringer Tilt

So here goes ive read about every thread there is on this topic, not really finding a answer.
1985 cimiron with 5.l stringer outdrive, last year the tilt quit raising would go about 3 inches then stop, you could bump it up until the motor heated up, wait a little bit the bump it up again, this is what ive done the past two weeks.
New Battery,
4 new solenoids
New tilt Motor
New tilt Switch
New worm gear and shaft.
New clutch pack
New bushings and seals
new hammer coupling( old one was OK but replaced any way)
New caster gear.
After all that same issue but if i take the weight off the motor and hit the switch it goes up, have rigged switch at the back of the boat for loading/trailering, but really want this to to work right, motor goes down fine.
could it be the sierra aftermarket solenoids,
really at a loss here

I'd do some voltage drop tests- the fuse holders with the 50A fuses in them like to get full of corrosion - can get new fuses where they sell car stereo gear. I've had success just using emery cloth and contact cleaner
file all ring terminals at relays shiny both sides and nuts and washers too

I've had some success putting 2 gaskets under the clutch cover. I believe the parts book calls them shims so makes sense that some may need two

Make sure intermediate housing and engine etc all grounded well