Please! Need help on tires and wheels. Urgent!!!

Are the wheels Ferrari wheels? The original 16" sizes, when they were provided on the later quattrovalvole models, were front wheels 16" diameter x 7" width, rear wheels 16"x8".

Original tire sizes are 205/55-16 front, 225/50-16 rear.

A great way to see available tires is to browse on Tire Rack - Your performance experts for tires and wheels , an online retailer in the US. You will be able to see what tires are available in that size combination - you want to search for tires by vehicle, enter the 1981 Ferrari 308, it will show original equipment size of 205/70-14, then in small print it will suggest "Optional tire sizes available in 16" diameters" - click on the "16" " in that line, and it will show 3 rows, first says Optional 16", then second/third rows say "Front Optional 16" and Rear Optional 16", with the sizes I listed above. Click beside there on the box that says "View matching front and rear pairs" - to me right now, it shows 37 models of tire that have those matched sizes available. You can then deselect options on the left side to filter the list, for example turn off some of the racing tires.

The latest Extreme Performance Summer and Max Performance Summer tires will all have a lot more grip and traction than was available in any tire from 1981. Some owners are happy fitting grippier tires than the car was designed for, some prefer to select tires from the Ultra High Performance Summer category of Ultra High Performance All Season category, thinking that they will be closer to the original tires' characteristics.

 

Some of the people here that has the 16s usually goes for the 17's and uses the size:
Front 225/45/17
Rear 255/40/17 or 255/45/17

 

Your tires are too tall.
Use either the original sizes listed already or use 225/50-16 and 245/45-16.
Look for Bridgestone RE-11's, if they are available they will be great.

 

I bought new tires for my 1984 308 GTS QV in 2012, right after I bought the car, replacing 12 year old Pirellis. On my original 16" wheels, I bought the original size 205/55-16 and 225/50-16 tires, the model Michelin Pilot Sport A/S3. I don't need or want the extra grip from the wider tire sizes, and in fact went with the best performance all-season tire available to keep safe performance on those spring or fall mornings where temperatures can be near freezing.

I have another set of wheels, the BBS E50 mesh style, with those same size tires, but with the Continental DW model. These are an ultra high performance summer tire, still not quite as grippy as the extreme or max performance tires.

The best performing summer tires in the dry will almost always also be the best performing tires in the wet - only some R compound street tires with very shallow or minimal grooves will have poor performance in the wet. Otherwise, buy great summer tires, and they'll be better in the wet than lesser touring or all-season tires.