One potential problem is that one of the credit bureaus (EX? maybe) stubbornly reports HELOCs as revolving credit rather than installment loans. So if you use a good chunk of your HELOC, it's going to look like you have gone berserk with a $150K CL credit card.
You might want to ask your lender how they see their other customers' HELOCs report. I've been told that even when the lender requests that they be posted as mortgages, the CRA won't always comply.
Supposedly installment loans like home equity loans and mortgages don't affect scores all that much, since your monthly payment is fixed, and you don't have a lot of easily available credit tempting you.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007