306 vs 308? vs 331

[OonDeanisS]

my brother just emailed me this...

hey do me a favor i cant post on stangnet....can you write something asking if i should go with a 306-308-331???? i dont know and i think that coast high performance has raised the price on the 331 so i think i might just go with the 306....and if thats the case, im ordering it like next week. but i kinda want peoples opinions, b/c im not sure what would be the best to do. thanks

 

[Black331Stang]

well if hes looking for an increase in HP over the 302 hes not gonna find it with the 306, a 308 is just a waste...so its between a 331 and 306. so if he wants significant power over the 302 go 331 cause 306 is the same thing

 

[93steeda]

I'd like to know the usual hp increase with a 306 myself.

 

[5spd GT]

I'd like to know the usual hp increase with a 306 myself.

You could see anywhere from 4-10 horsepower depending on how bad you need a rebuild...usually no more than 4-5 horsepower...its practically the same...most people just do a 306 to get a freshened cylinder wall...

A 331 will definatly be a noticeable power gain...

David

 

[N8Miller]

As NitrousGt told me, "there is no replacement for displacement".

hearing that, i opted for the 331 over the 306. i only wish that i would have fully upraded my internals to a forged crank and I rods (maybe is H---which everone is better is the one i wisht hat i would have gotten)

Go 331 with a nice cam.

what mods are done to the car?

 

[Black331Stang]

H beam rods are good, y are u saying u want I's? u wouldnt be able to tell the difference. and what are u doing with your car. forged wont give u power, actually just more unwanted wieght unless u really gonna be beating the nuts off teh motor and throwing everything at it. did u get a shortblock form KC? if so how much was it?

There is Really NO difference ina 302 and 306...everyone is usualy like oooooooo 306. woopie, means $hit. maybe a few HP only cause by freshening up the motor not really more cubes. u wont feel a difference.

 

[5.0 HOtrain]

Well, apples for apples a 331 is only going to make around 25-30 more hp's than a 306. So depending on price difference go with whatever is in the budget. If I were doing a n/a motor under or around 400hp and was going to keep it that way, I would go with "I" beam rods, they are quit a bit lighter than the forged H-beam. I went all forged because I plan on making around 600+fwhp n/a and then add some nitrous on top of that. What's you're brothers plans/goals/future ideas, and most important, budget
mike.

 

[N8Miller]

H beam rods are good, y are u saying u want I's? u wouldnt be able to tell the difference. and what are u doing with your car. forged wont give u power, actually just more unwanted wieght unless u really gonna be beating the nuts off teh motor and throwing everything at it. did u get a shortblock form KC? if so how much was it?

i know that the I beams wont make any more power, but it will give me more peace of mind when i start to spray on it. i know it will be fine with some good tuning, but i should have gotten them while the motor was being purchased.
yes, its aKC econo 331 stroker---around 2300ish. great investment.

 

[Black331Stang]

so the I beams are overall better than H beams???

No way only 30 HP more...yeah maybe if u shove all the stock crap parts back on. But the 331 can take alot better bigger, high flowing parts than a 306, resultingin more power. no comparison.

 

[TIMMY2734]

i beams are lighter than h beams. And for a street car, i beams should be plenty strong, assuming that you use a quality rod. If you are using a stock block, than i beams and a good cast crank should be more than plenty. Usually, the first thing that will break in the short block is the block itself, not the crank or rods.

Heres a good thread about which is stronger
http://www.corral.net/forums/showthread.php?s=&threadid=375712

 

[StreetStang37]

a 331 is only going to make about 10% more power than a 302 with the same setup.

 

[JadeFalcon]

what is with this 306 and 308 mystery, its just a bored over 302! its like 4 cubic inches!! Its like .82 horsepower! G#%@%^@$#^$#@&$%

 

[OonDeanisS]

his mods are as follows:

underdrive pullies
hooker headers
bassani off road X
flowmaster 2 chambers
3.73s
tremec 3550
steeda tri-ax
FRPP adj. clutch cable
FRPP heavy duty clutch
lightweight flywheel
FRPP 9mm wires
Performer heads
Performer RPM intake
1.6 roller rockers
F303 cam
FRPP timing chain
30 lb/hr injectors
Aeromotive Fuel pressure regulator
Eibach sway bars
Eibach road race springs
Eibach subframes
poly bushings
X drilled rotors
Koni 5-way adjustables
Corbeau seats
cold air intake
fluidyne 2 core heavy duty alum. radiator
alum. driveshaft & loop
75mm MAF
70mm TB
190 lph fuel pump
aluminum fan

 

[Ryan91Saleen]

would a gt40 motor work?

 

[Black331Stang]

holy sick avatar ryan...did whytry do that for u??

if those are his planned mods he will have a pretty stout 331. get a new custom cam and a 255lph fuel pump and he should be mid 300 RWHP.

StreetStang- so your telling me that a 302 will have 250 Hp and a 331 qould only make 275???? U have to think that a 331 will need more air, resulting in the acceptance of bigger/higher flowing parts which then results in more overall HP.

A 331 WILL have significant power OVER a 302/306

 

[OonDeanisS]

he has all that stuff now, the only planning hes doing is the engine size, and he thinks he'll be over 400 rwhp