LT4 finally built- wanna know what I did?

Well, it's not done but the job is in progress. I have a 1996 Firebird Formula that I bought about 2 yrs ago from it's original owner with approx 60K miles. Nothing was done to it, and it was bone stock. I began right away learning what I wanted and bang-for-the-buck improvements. My first dyno run (stock) on a Mustang style dyno yeilded 230 rwhp. I then put in a K&N airfilter and removed the baffles from my hood scoop to make the ram air hood more free flowing. I put in a 160 thermostat and put in an MSD 6AL ignition with a blaster coil and 9mm wires with NGK TR55 plugs. I wouldn't recommend this as it's not a great investment. Over $300 for the ignition and not much gain. Then I did what I should've done in the first place and installed Hooker long tube headers with a 3" stainless catback and no catalytic converter. (luckily MI isn't an emission controled state) I highly recommend JET HOT coating for any new headers. They have a life time rust-through warranty. The shop who installed mine, said they were ceramic coated, but it's been about 1.5 years and they look like crap with rust. Probably have to replace in another year. LEARN FROM THAT!!!! I welded in subframe connectors, and for those who hate those annoying little rattles that pop up from time to time in the cabin, this fixes those immediately, plus stiffens the ride and makes the shocks do they're job rather than make the frame absorb the pot holes. Next I put in a 2800 RPM stall torque converter w/ lock up and a secondary trans cooler. At this point I had my PCM tuned to eliminate smog devices and lower fan temp activation. Then I installed 3.73 rear gears with a new Eaton posi. WOW- what a difference. Another tune for the PCM to calibrate the speedo and I was on my way. Lastly, a timing and opti-spark distributor issue forced my hand and I put in the rest of the components that I had waiting in my garage (LT4 ported/ polished heads... <ask me the flow #s>, LT4 ported intake, 58mm throttle body, 30lbs injectors, comp-cam 305 camshaft and LT4 extreme duty timing chain and ARP fasteners and head bolts and Fel Pro Performance head and intake gaskets)

I had the heads decked 0.035" to boost my compression to 11.1:1. I've heard similar set ups without the added compression and bigger throttle body can make upwards of 425hp. I'm thinking mine might make upwards of 450hp. But I'll be sure to make a dyno run and post the figures for all to see. With as much torque as I'll have to my rear wheels I'm afraid with my 3.73 gears, and 10-bolt posi and 2800 verter I'll never be able to hook off the line. I don't want to upgrade to a 12 bolt just to run slicks on the weekends, as this is my daily driver, but if I beefed up the rear suspension with boxed lower control arms and QA1-HAL adjustable rear shocks and preload the hell out of them... will I break my differential? I've been told I'll be fine as long as I don't run slicks or stickies, just curious for other input. Also, if you're stuck along the way of your mods and need guidance I can shed light on what I learned.