Any PC 288, whether it's 288(a) or 288a, is among the most serious crimes in the penal code. I can't tell what your question is because your bf has admitted and then recanted at least twice.
If your bf is listening to jail house buddies he is a fool. He should be working with a lawyer on this one and no one else. He is subject to a strike and lifetime registration as a sex offender as well as the state prison time. Fair warning: he's not going to get a better deal unless he goes to trial and is acquitted.
He may not get a better deal in terms of a single count, but he may get a better sentence than the maximum of 8 years. With no record and other favorable factors he may be eligible for less time in prison or probation, depending on the exact charge and any unusual circumstances. The judge may have given an indication of his intentions during negotiations. All the facts and circumstances are important in these cases. Registration is often a more significant consequence than the actual time in custody.
If he is charged with one count of 288(a), the maximum (assuming no conduct allegations or sentencing enhancements) is 8 years. A plea for 8 years on a single count doesn't sound like a good deal at all.
If he was charged with multiple counts and the exposure was much higher, then 8 years may be a great deal. It's just impossible to tell what his maximum exposure is without knowing the exact charges and all allegations on the charging document filed in court.
The best person to advise him about this? His attorney. Not some other inmate. Not any of us on the internet. His lawyer has access to all the necessary information to actually answer this question.