Thanks Big Chief!!!

I would like to be able to hop in and drive the highways, I am in California and like to hit the road! I want power and dependability. I am setting up like a Pro touring car, power on demand and road handling. I am not looking to do a numbers matching car as mine was one of the few Firebirds PHS did not have anything on!
I dont plan to race but you cant go anywhere here without running into the many Mustangs and Mopars.
I have 2 engine choices, I have a 400 Block that has been at a rebuilder that shut down during Covid but is back and in operation. A lot of how I think has changed. The 400 is already bored decked and supposedly parts were bought for it. At issue is they "misplaced the 61 heads that it had, They are replacing. I really did not have it stroked or anything but going with forged pistons etc. The heads were supposed to be ported, polished and bowl matched. I have a performance RPM manifold, I do have the higher rated EFI for up to 600 HP (Go EFI 4), but only as I had to do that to get the "Tumble polished" Color
Petronix Ignition conversion, Tomahawk Windage try,
Comp Cams
Cam specs are
224/230@050,
.477/.480 lift on a 110 lobe separation angle
It was just a mild rebuild but not sure if I am going to get even 400 HP out of that.

A friend of mine offered me a decent deal on a 428
Pontiac 428 Engine originally from a
1969 Grand Prix SJ.
Standard bore 4-bolt main
428 code XF and block casting number 9792968
This 428 has been completely disassembled, cleaned, measured and inspected than reassembled and now sits on an engine stand.
Engine details.
1969 # 62-cylinder heads high perf
correct 69 intake
correct 428 distributor
all parts are date coded within a2 week period

I know i have a lot of parts already for the 400 but I have been leaning towards the 428, maybe more out of frustration at the time it has taken for the 400 to be completed or the novelty of a bigger cubic inch engine

I have a lot of people telling me regarding both engines to stroke it and or at the minimum get aluminum heads. I have been talking with a gentleman from San Diego, John who has been a wealth of information for me as well!
I never thought of myself as any type of real purist but I find it hard to just dump the 61 & 62 heads, although there may be an issue with too high a compression ratio with todays gas.
I would love the horsepower but for me this will not be a 1/4 Mile drag car but one that can do the winding roads and still have the lower end stay together! a lot of low end and mid range
I also want to keep in mind I may convert to a 5 speed
I don't have an unlimited budget but i do have funds to go forward and can just put the 400 together with what they already have and put aside for another project
I don't need to build the 428 with the parts I already have for the 400 other than the fuel injection, those parts were paid for a few years back

I would love to see around 425 to 450 HP if possible with the cast iron heads but will go with Aluminum if necessary but do not want to wait months for the heads

Thank you!
Berndude