First off I took the realtors suggestion and listed with the property management company he promoted to me.

Current HELOC rates are typically 8-10% depending on your credit and lender, though some banks offer promotional rates.

I also doubt very seriously that any brokerage/custodian is going to allow this kind of loan with 401k assets; it's likely going to need to be a 401k general purpose loan, which is highly regulated (as someone else mentioned). 

I special purpose equipment setup. 

While I would have built $150,000 in equity, the cash flow simply doesn’t work.Now, let’s compare this to the market conditions when BRRRR was highly promoted (pre-2020).Interest Rate: 4.75%Monthly Payment: $3,057/monthRent: $3,600/monthIn this scenario, I’d be making over $500/month with $23,000 left in the deal, resulting in a gross 26% cash-on-cash return—an excellent deal.As you can see, rates and prices play a critical role in the viability of the BRRRR strategy.

It is a standard conventional loan and was offered as a promotional financing by builder at the rate of 5% for investors. 

It's very possible that whatever change might happen won't be in affect until 2026 also.It's also worth noting that any depreciation taken for the property for rental purposes doesn't become part of the Sec. 121 exclusion should you choose to take that in a future year.

Please extend an invitation to your tenants to visit me in my home (1925 block/stucco construction - a dang bunker for all practical purposes)...footsteps bother them? 

So, for the interest paid on the loan from August through December, who can claim the interest for tax purposes?

What's the purpose of trying to get a loan when I have to pay that much out of pocket just to get it?