1974 firebird formula engine swap and parts identification

[rogermayhem]

i am new to forums all together. in fact so new this is my second time typing this. i guess my first one didn't post? idk i hate computers. 24 years old and i cannot stand computers.
well anyways. i purchased a 1974 firebird formula. the guy i bought it from lied about alot of stuff on it. good and bad. it has forced me to learn about my car. my dilemma is i don't know the specs on my car. i did some research for parts and casting numbers. some stuff is true and some stuff he lied about. but anyways. i have a sbc 305 in it currently. the guy told me it was a 383 stroker at first but i may have misheard him and it is a 305 stroked with a 350 crank. do i want to do and engine swap or a rebuild? i don't know what would be better to do. my 305 specs i found are
305 cast # 14010203
yrs. 80-85
car & Truck 2-bolt Passenger stick
heads cast # 14022601
267/305
yrs. 79-86
1.72/1.50 1.84/1.50 58cc
i currently have access to a 92 Silverado Z71 4X4 350 from my buddy. haven't gotten the block numbers for that yet.

also other pats of the car i don't know much about.
the tranny. i cant identify it by the pan shape. its also got a b&m shifter in it. cant find model numbers or anything for it

how do i know what kinda HP im currently looking at or a rough guess. it currently has a edelbrock 1406 performer 600 cfm and a edelbrock rpm performer intake.

i think the rear end is a 4.10 so he tells me. all i know it does take off with a lot of force. and if i go down the highway at 55 it sits at like 3500. its been driven like that for awhile so im guessing its handling fine. how can i know for certain what rear end i have?

the radiator is completely custom fit in by cutting the shroud and fabricated brackets so i know its not meant for that car. it is a fluidyn is all i know. theirs no numbers on it that i can see. it has a built in oil cooler as well which is currently not hooked up. is it sufficient? i used to have heating issues in it when idling untill i made a fan shroud for it. its make shift for now until i decide what direction i want to go with the engine. but that fixed it unless im driving and then have to idle at a light for like 10+ mins.
it does have an MSD 6AL CD Ignitions 6420. the distributor is an accel hei super coils 14003. if theirs anything else yall need to know please ask so i know too. sorry for being such a newb. i normally don't seek outside answers as i don't like conversation. but its time to break my comfort zone. if theirs anything you guys can suggest or ask or just inform me please do so. i have this irresistible urge to just learn more and more about my car. only work ive done on it is body and exhaust and basic maintenance with plugs and gaskets. well fabricating things. that's what i enjoy doing but i want to branch out. sorry for my terrible spelling and grammer and forum etiquette, that's another reason why i dont like conversations. i talk worse then i type haha.

that's what it looks like under the hood maybe it'll help answer any questions. also don't laugh at my shroud like i said its still a work in progress

 

[melsg5]

it all depends on your budget, not much you are going to do with the 305. The 350 you can turn into a 383 with a 400 crank or just buy a built crate motor or switch back to a Pontiac engine.
Maybe this site will help you ID the transmission. http://www.nastyz28.com/chevy-transmission-identification.php
On the rear end if it's a posi rear, jack up the rear of the car, trani in neutral with parking brake off. Put a chalk mark on driveshaft and turn either rear wheel 1 turn while counting how may times the driveshaft turns. If a 4.10 the shaft should turn a hair more than 4 times.
The engine probably makes in the high 200's at the moment.

 

[rogermayhem]

cool deal. i will check the rear end at first dawn. as for how much im willing to spend.itll most likly be around a grand. not alot but enough to the patient craigslist watcher. i got the block number for the other 350 my buddy has. 14093638. the heads im still waiting to hear about. but if its vortec heads on his z71 will a basic rebuild of the 350 be a better performer then the 305 i have now? when i do this rebuild id like to also do a dual 4 barrel tunnel ram set up. will the 350 handle it or should i beef it up? i plan on making it like bullet proof and use forged parts to ensure its longevity. i dont really plan to dog the car as i actually odnt like to speed or do anything crazy. just like cruisin but i like knowing i have the ass under the hood i need when i need it or wanna show off haha.

unrelated. theres an ad right now on craigslist for a 350 vortec block 10243880 and heads are 10239906. the guys asking 500. intake manifold to oil pan. is that a good buy? all good conditon other then the usuals for a rebuild. would yall suggest that over the other 350?

 

[melsg5]

I believe almost any 350 will be a better starting point than a 305. You cannt just slap a dual 4 barrel on any old engine and think you are going to have something streetable. A dual 4 barrel engine requires a engine that has sufficient air flow to actually use the volume of air that duals will produce. If you use a carburetor flow calculator such as on the Holley web site you will probably come up with a figure of about 600 CFM. If you use a vacuum secondary that is properly adjusted you can even go as high as 750 CFM. On a barely modified engine using a dual set up you will step on the gas and car will just not move compared to a single carb on a proper intake. On good buys you will have to see what the going rate is on craigslist or ebay.