306 and 331 cost difference

[fiveoho]

havent set anything in stone yet, but its looking like i will be doing a fresh NA 306 with a mild H/C/I , bigger TB and MAF and injectors, yadda yadda yadda...

been kicking it around about doing a 331. well, i am on a budget....
and i have a deal lined up for a 3550 trans (so there goes some of my $)

my question to you guys: whats the cost -start to finish- to build a 306 and build a 331? and what kind of power/torque difference am i going to see between the 2?

ive spoke to some reputable mechanics and performance shops about this. i was told that a 331 will make -around- 60 more rwhp than a 306. although he said the torque diff was greater along with the seat in the pants feeling.

if theres not a huge power gain between the 2 but there is a hefty price difference, i cant justify doing a 331 with my T5 ( it has issues) when i can do a 306 with a 3550

thanks guys :SNSign:

 

[Modular2v]

with a 331 you are going to have to go with bigger heads to take full advantage on the extra cubes....but yes! there is a pretty big seat of the pants difference between the 306 and 331

 

[89white50]

bigger heads, larger injectors MAF, would probably get a more serious cam...obviously a new or get ur crank stroked. longer rods. The cost difference i could see beeing 600-800 dollar difference. But in the end well done 306 Daily drivers can run around 330 rwhp area na. a 331 you can get closer or 400 rwhp na fairly easily and still have good drivablility.

 

[5spd GT]

About a 30-35rwhp difference if you use the same heads and all that you were going to use on your 306.

A 331 needs to have a new crank, pistons, rods along with a different flywheel and balancer.

A 306, you can reuse your stock crank/rods/ and you need new pistons. You can reuse your flywheel/balancer.

Upgrading the stock t5 is a good idea.

Good Luck!

 

[fiveoho]

i appreciate the posts guys. keep 'em comin...


So are we lookin at about a $1000 difference between the two? more...less?


if i can get say, 315rwhp out of a 306....id be pleased. guys take a look at my signature down there and see what u think....is 315 a realistic #?
like i said, nothin is totally set in stone but its pretty close.

thanks

-331 : probably not a good idea with a worn T5?

 

[DMAN302]

Heads might be better suited for a 331...306 perhaps a 165 head would be more in line. Next you've not mentioned a cam..the cam is a significant part of the puzzle when looking for the kind of numbers your wanting. Custom cam would be ideal with the components listed to meet your goal.

 

[fiveoho]

Heads might be better suited for a 331...306 perhaps a 165 head would be more in line. Next you've not mentioned a cam..the cam is a significant part of the puzzle when looking for the kind of numbers your wanting. Custom cam would be ideal with the components listed to meet your goal.

yea, youre prob right about the 165s. 185s might be a tad much, but i sorta considered those in case of any upgrades later on.

far as a cam goes, i listed the trickflow 2001. i may go custom grind tho?


thanks

 

[bdazzgt]

Custom would be your best bet, they are made to take full advantage of your combo, not just a general combo. They are a little more pricy i bought a comp Xe and after it was all said and done $50 more and i could of had a bad ass ed curtis cam sitting my motor right now.

 

[Rick 91GT]

The price difference between the 306 and 331 shortblock is actually within a few hundred dollars, atleast on the stuff I build..

With the stroker it is best to go with a 28oz in balance, a new SFI balancer will run $175, flywheel depends on steel or alum and brand.

Custom cam would be best to really get the bet power and drivabilty.

 

[prochargedfox]

I was going to build a 306, but decided to go with a 347. The price difference was acually about $100. You just have to look for good deals. Good luck with the build.