I would need to know what your long term goal is for your Stang
but
Based upon what I saw
Looks like you were going for the OEM GT40 based combo
Depending upon parts used

Those combos yield 245 to 285 rwhp for an average amount of power
Don't know what your long term budget is

but
A couple of thoughts for ya
Based upon the fact you wanna be at 300+
With the 5.0 you need to move up to aftermarket parts for NA
of
If you keep the OEM stuff you gotta go PA
With NA and aftermarket parts ... 3K is only a drop in the bucket
1200 heads
250 rockers
530 intake
350 custom cam
320 lt's
180 mid pipe
400 gears
600 tune
That short list is only the key parts and don't inlcude supporting stuff
like fuel pump, valve covers, head bolts, push rods, etc
You don't say what kind of trans you got but if an auto
The above combo would be a real dog with one unmodified
so
You would need a high stall tc and shift kit ... $$$
Now ... the above is for new parts
and
I quickly threw up those numbers from a very quick estimate
BUT ... You can see the 3K is not enough for a quest of 300+
Lets now go in a different direction
Keep your OEM heads and cam and use juice or a blower
With PA ... the choice in parts are not nearly as critical as with NA :Word:
I myself don't care for juice ... but ... It is there for you
S trim would be nice

but
You've not gained much with how far you can go with only 3K
You pony up for a kit
big inj's
tune
etc
Again ... you've gone way beyond the 3K
Lastly ... The Windsor option
You gotta gather up the parts to make it fit such as
hood
flywheel
headers
hb
etc
To cut to the chase ... 3K ain't gonna take you all that far
I'd say the NA route and S trim route are about the same amount of money
but
You make more ponies with the blower over the NA method
Please ... Don't think I'm trying to rain all over your parade
It is just a fact
Speed cost money
How fast do you wanna spend
Grady