Thanks for sharing your method. I have made a couple of comments below - not to criticise the method you used (as you were following the recipe it in good faith) but to help with some background information for when you prepare your next batch.
Firstly the cure itself.
Bacon would have been traditionally cured using salt that contained Potassium Nitrate (Saltpeter) and the Nitrate would help delay the rancidification of the fats and help develop the traditional pink colour in the meat. One of the main preservation requirements for longer term storage though is the protection against micro organisms (like Botulinum) for which the Nitrate decomposition product, Nitrite, is required. This is why when curing most meats that will be stored we will use a mixture of Nitrite (for immediate protection) and Nitrate (for longer term protection). Both the Nitrate and Nitrite will give the colour and will help preserve the fats.
Recent studies though indicate that the Nitrate, when heated to high temperatures - as in frying) are more readily converted to nitrosamines which are indicated in causing increased risk of cancer. Because of the the USA have banned the use of Nitrates in the commercial production of bacon and the EU recommend against its use - though they have not been able to ban it due to the number of "traditional" cured meat products that already existed throughout the EU countries.
There is no legislation in place for the production of bacon at home (!) but you may want to err on the side of caution in the future and follow the commercial guidelines.
Yes, the use of Cure#1 (which contains Nitrite only) will be a good move for next time .
The quantity of cure you used.
You used 8 g of Potassium Nitrate PLUS 1000 g of salt. Below I have rounded the calculations to 8 g Nitrate IN 1000 g salt to make the calculations simpler.
You used 120 g (0.12 Kg) of Cure for every Kg of meat - which results in 8 x 0.12 g of cure per Kg of meat = 0.96 g of Nitrate / Kg meat
To convert to mg/kg (or Parts per Million - Ppm) we multiply by 1000 = 960 mg/Kg (Ppm) which was applied to the meat.
This needs to be compared to the commercial permitted limits of Nitrite - which is 150 mg/kg. Taken at face value you used over 6 x the maximum commercially permitted amounts of cure. I do not know your precise method though, and if you lost some of the cure during the curing process (e.g. losing some of the produced brine) then the amount you finished with in your bacon would be less.
I am not surprised that it tasted salty as you applied 120 g of salt to each Kg of meat. This would have resulted in a salt concentration of 12%. The average person finds a salt level of 2.5%-3% ideal and over 3% starts to become increasingly too salty. To overcome the saltiness in the bacon sugar is often used, as this helps reduce the salt taste when eaten. Sugar is typically added to the cure at a rate of 50% of the salt.
Using the Cure#1 in bacon
When your Cure#1 arrives here is a good rule of thumb for calculating what you require
For each Kg of meat use 2.5 g of Cure#1, 22.5 g salt and 11 g sugar. During the curing time do not lose any of the brine produced as it needs to stay in contact with the surface of the meat.
Good luck with your next batch and we would love to see more photos