Setup Advice on an early KZ kart

Anyone has any experience in setting up an older KZ chassis? I am rebuilding my kart from scratch during winter and instead of randomly putting it together i am wondering if someone has any experience/advice to offer on the kart setup? It’s a late 90s CRG chassis, i tend to struggle with rear grip and i have never managed to get the rear wheel to lift but my pace is not bad, i am not sure if rear wheel lift is a thing on gearbox karts. It’s challenging to drive it and i have to add a lot of effort to drive it. The plan so far is to put the seat further back, axle in lowest point and at this stage i have zero experience with the front of the kart and probably where i need a bit of advice.