I got on e-bay found a Wiseco gasket kit for 86 - 88mm bore
for 88-90 zilla.
costs to germany after 65, 67 €
which is ok?

Greeting Frank

Jawzys .
Part: Top End Gaskets
Brand: Wiseco
Part Number: W5150

Specifications
Gasket Position: Top End
Bore Range: 86.00-88.00 mm

Application
Make: Suzuki
Model: LT-500R QuadRacer
Years: 1988-1990
Made from the highest quality materials
Engineered by Wiseco to insure compatibility with Wiseco products
Each gasket kit is sourced in-house by Wiseco to find the most