I have this PSU - CVS MP-700... guy in the shop told me it was 700watts and I thought overkill to replace my old TRUST 570 W... anyway (not much info about the CVS MP-700 around)

On the PSU label it says: CVS 700 :

3.3V - 15A , 5V - 16A, 12V1 - 23A, 12V2- 23A, -12V - 0.5A, 5V - 3A

So knowing not much I think ...

V A Watts 3.3V 15 =49
5V 16 =80 12V1 23 =276
12V2 23 =276
-12V 0.5 =6 5V 3 =15

Total Watts = 702

But I also think this is probably the maximum output and that to be on the safe side I should probably assume a safe output is more like 75% of this figure ... say 530 Watts ... Q 1 Am I right to think this ?

Also I am planning to get a bigger card - (current card has no 6/8 pin just off the mobo GTX 750 ti TDP 65 w) something like a GTX 1660 Ti TDP 120 Watts

I put a build together on pcpartpicker and it says the total wattage (including the new 1660 ti card) will be 302 watts - I did the same on another site and it came up with 300 watts too.

The CVS MP-700W psu only has 4 leads - 1 x 20+4 for mobo 2 x molex 4pin + sata 1 x 4pin - that goes to the mobo too - for nic maybe

So my plan is to put my ssd and hdd on one of the molex+sata leads and put the 8 pin to the new 1660 ti graphics card on the other molex+sata lead...

I don't see a big load being drawn from the molex because half the power will probably come from the mobo anyway... I am assuming mobo will give 60 watts and molex will do the same if it needs to.

Q2 Is this going to work ok - Am I right to think this ?

Thanks