427 heads on 454 block???

Brand new on here. just signed up so i could ask this question.
Here's the deal, I gotta a 90' 454ss truck.

Motor-
03' GMPP 454 crate moter .060 over
edelbrock multi-point fuel inj. system
edelbrock performer intake
edelbrock elec fuel pump
msd billet dist., cap, coil
accell 300+ racewires
billet underdrive pulley kit
k+n 14" round (cowl inducted)
Stock throttle body (blah! its killin me i know. being replaced soon)
STOCK HEADS- i hate em!
edelbrock tes headers (1 3/4") w/flowmasters 40 duels (no cats)

Run fine for what it is but i know better heads will open things up a ***
I have a set of #3872702 66' 427 heads. I would like to clean em' up a bit. valve job, port match, new rockers, springs, valves......etc   and make them work on my truck. First off, will they work? and if so what will it take? gaskets, hardware, machining? help please.  

they are 66' closed chamber("bathtub"), lg oval port, 2.06int/1.72exh
i finally talked to a guy that runs an eng. machine shop close to where i live.
i heard from 3 different sources that hes been building BBC's for over 20 yrs.
told him everything i had what i was looking for, idle-5500 pwr, cast #s, etc....

he called me back 20 min later and said "yeah these heads should actually give you a pretty good setup. it will raise ur CR to 9.5-1."

ill be doing some port work first(this will make my 4th set of heads)
as well as port match to my edel. intake
he will be doing a 4-angle job, harden the seats, and new guides.
ill be putting ssi stainless 2.19/1.88 valves, new springs, and crane RR's back in
keeping the 7/16" RA studs, 3/8" Pushrods, and 3/8" guideplates  

How in the world do you have a multi-point fuel injection setup on a regular performer intake manifold with a stock throttle body. Do you have any idea what you're talking about?

I don't know how your machinist is going to harden the seats either.  

its an edelbrock intake AND edelbrock mpfi. basically same as the performer but it has injector bosses going into the top of each head. supplied by billet fuel rails with Pico injectors. the stock throttle body(the stock 2 barrel is 52mm(maybe 54) mine has been bored to 68mm and replaced with thinner alum shaft and blades) has the injector pods removed, bascially making it an a carb with no fuel supply, just used to control air intake. (by means of TPS). I know of about 20 other 454's running the same system. it gave me abt 70hp / 85ft/tq more to the wheels. i really need larger inj. and a FPR to get it completely dialed in though. the throttle response is great, ecspecially rollin down the hwy doin 70 or 80 and just nail it. no lag whatsoever.  

its an edelbrock intake AND edelbrock mpfi. basically same as the performer but it has injector bosses going into the top of each head. supplied by billet fuel rails with Pico injectors. the stock throttle body(the stock 2 barrel is 52mm(maybe 54) mine has been bored to 68mm and replaced with thinner alum shaft and blades) has the injector pods removed, bascially making it an a carb with no fuel supply, just used to control air intake. (by means of TPS). I know of about 20 other 454's running the same system. it gave me abt 70hp / 85ft/tq more to the wheels. i really need larger inj. and a FPR to get it completely dialed in though. the throttle response is great, ecspecially rollin down the hwy doin 70 or 80 and just nail it. no lag whatsoever.  

Oh my god, a fuel injection setup gave you a 100-130 horsepower gain at the flywheel. That is either not true or nothing to brag about. If that indeed happen (which I doubt) your first tune must of been HORRENDOUS.  

that is why edelbrock custom burns you a chip for ur comp. when you
install it. Obviously you would have a hell of a time trying to tune
the setup if you didnt start with the computers.
i ran a 13.27 very first run after installation.
got it down to 12.74 now after playing with the timing
and throttle body a little bit.  

What was your TQ&HP at the wheels before and after the swap?  

I guess it would depend on what you swapped from but in the cases I have read about swapping from a carb to a FI setup, there was little if any difference in HP. In some cases the carb developed more peak HP.  

Everything I've read about those swaps showed no HP/TQ gains but some would show a flatter power band.  

Check with GMPP and make sure their newer block is compatible with the older cyl. heads. May require a special head gasket.