Fox Trick Flow 170’s on a 331 Stroker

I currently have the TW 170's on my 347 and am looking to upgrade to bigger heads and cam. It runs good but if you're looking to go stroker it's obvious that you're looking for more than what the 170's can provide. Those are super heads for a 306.
For what it's worth, my 347 with the 170's puts out 360/395 to the wheels.

Years ago I had TW 170's on my 347. Made 371hp @ 6200 rpm on a mustang dyno. Go with the stroker short block. Don't waste your time with a 306, do the stroker (go 347). That'll be your foundation you can always improve down the road.

If you boost it, you'll get to max stock block limits without a problem with the stock 302 rotating assembly. So, if boost or spray is in your future, then just leave the displacement alone.

If you will stick with n/a, then stroking makes sense, but as Mike stated the 347 makes a lot more sense than the 331. Same price, same reliability, more power.

TFS 170s are good heads, and though they will not be optimum for increased displacement, you will see more power with them on a stroker than on a 306, assuming cam & intake support it.

Hey man,
I'd say go for it! Those heads are plenty enough to make a 331 rock n roll, and in countless chassis dyno runs I have seen VERY LITTLE difference in similiarly built 347s vs 331s. Are those heads the highest flowing model on earth?...of course not. However, they DO flow enough to support over 500hp, which in reality is probably more stress than you want on a factory block anyway; unless I miss my guess. And with that good intake you've already got, a well spec'd 331 with the right amount of static comp. to support whatever cam timing your wants and needs dictate, can and will make enough power to actually hurt itself...which should be considered "plenty" in any case, no? DSS makes a really nice, lightweight 3cc flat top for the TFS heads that hangs on a 5.315" rod, which will put you really close to 10.5:1, assuming a .030 overbore and just a clean-up cut on those heads, with a 0 deck. I'd say close your intake around 64-66 degrees ABDC, and stick with a 112 lobe sep, putting you in the 272-276 advertised duration range, with lift around .550 on both sides (provided the heads are sprung right), and maybe something like a 6-8 degree split. It'd be easy to tune, SHOULD get you in the 425-450hp range with gobs of torque, all before 6000rpm, which means it should outlive us all with proper maintenance, and it would run on 87 octane dog water as long as you don't get it hot. Trick Flow made 350hp and 370ft/lbs with those heads and a li'l baby cam with substantially less lift than the heads will support, on a 9.5:1 306, right?....well, if anyone disagrees that another point of compression, a little more cam, and 30 more cubes through a quarter inch more stroke should easily net a guy another 75+ ponies and the torque to go with it, I'm all ears. Either way, I look forward to updates on your build, and hope it all goes smooth and you have a ball doin' it, bud!

There is this option for the TW heads as well, several stages available. Depending on what you could sell your TW heads for and if you have good hardware on them already, you may be better off going this option if looking for better heads.

Good post, Ive got my block at the machine shop now and deciding on what 331 or 347 kit to go with. And a fresh set of Trick Flow Twisted Wedge 170s to go on. Should work fine for my street car. Looking for an easy 350/350, should suffice.

Take the extra displacement. It comes at no cost. There are reasons to build a 331 over a 347, but that's only relevant to high-boost applications and/or parts you already have. -Chris