10 vs 13 weeks cycle keeping gains

i have 2 options for 1st real cycle

1-13 deca test 300mgs pw

or

1-10 deca test 400pw

i have read over a 1000posts and it seems to me that 13 weeks might be better. you r giving your body 3 extra weeks to get use to your bigger size, and when u stop the cycle and start clomid your body might be able to keep more of your gains. 400 for 13 isnt an option beside my first cycle 300 of each should be enough
stats 37yrs 6'2 201lbs

what do you all think? thx for your inputs

I'd stick to 10 weeks with deca. You will want to recover from that asap, especially if it's your first cycle. It'll last in your body for 3 weeks anyway. If it were EQ, I'd tell you do go longer. Keeping gains has more to do with post cycle therapy, diet and training. Don't expect to keep everything, but do everything right, and keep majority of it.

Good Luck