dan0617

Anyone know if the Trick Flow Twisted Wedge heads that are now discontinued work on a stock L98 bottom end? They were the G2 heads, part number TFS-31500002. I've researched the net a little and can't find whether or not they will work with stock pistons. With the relocation of the valves the way the heads are designed it scares me that they won't work without special pistons. I didn't buy them yet so I can't check clearances, and I don't want to buy them if they won't work. Anyone know why they quit making them and now make the 23 degree head that doesn't flow as well?

Random84

they SHOULD work - but every setup - like cam advance, etc (and gasket choice) can effect things.

You will want to get some modeling clay and check clearances to be on the safe side. I would be comfortable with the purchase as they were designed for the typical SBC 350 in mind. A call to trickflow tech support should alleviate any concerns though.

They were probably discontinued due to a sales/profit issue, although if memory serves they were slightly more efficient than the standard 23* heads - just arguably not enough to justify the unusual valve arrangement for most buyers?

cv67

I cant remember if you had to use their pistons or not, that was a long time ago, I know the Ford boys really liked em..

makn u shiver

I heard those heads where taking out of production because they had problem with the valve seats working loose.

doug_dayson

I've had them on my C3's 406 for over ten years (.485 lift or so), no probs excepting a batch of them came with bad K-Motion Valve Springs back in the day, but Trickflow swapped them out etc.

It's important to make sure their Pushrod length is correct too.

REDC4CORVETTE

If you are using a large cam I had to cut the piston in my buddies to clear the valve.
The normal valve recess in the piston will not work.I can say tooooo much work for what you can get out of them.Buy the correct piston and buy the heads and keep it simple or stick with normal heads and pistons.
They do make twisted wedge pistons to fit the heads .

BadSS

I totally agree with Red.

You can only run about 230 - 235 degrees duration and some where around .530 lift with the 12* (G1s),, probably a little,, but not much more with the G2s and their 14* valve angle on a standard 23* piston. That's a VERY rough estimate and you're going to have to make sure as stated above to check the valve to piston clearance on ANY cam you run with those heads. However,,, I know a 218/228 - .492/.502 lift - 110 spread cam with the intake lobe center set on 108* clears TRW flat-tops.

IMHO, they're as good a set of heads you can buy for a small cammed engine, but if you're wanting to make over 440 short runner crank HP,,,, as Red said,, there are comparable heads that do not require cutting the pistons,, or special pistons.

Last time I check Summit's clearance section,,, they had slashed the prices on the SBC Twisted wedge pistons. You might want to check into that,, if you can get the pistons cheap and the heads cheap might as well go for it. With the money you save,,, you might want to call Art at Trickflow / Summit,,, to turn you on to the guys that were getting 320 cfm out of the twisted wedge heads after porting.

doug_dayson

I agree as the relatively small cammed street engine was their focus, (a relatively small runner head with great performance, good intake velocity and flow, plus a really good exhaust port as well).

For a warm street engine they're great, though for a hot race engine I'd certainly use something bigger.

aklim

The only way I would use them for more than a paperweight (that is what it turned my LPE 383 motor into) is if the heads were stripped bare. I got a set with their heavy duty springs and found out later that one spring broke. Took the head off and found the valve hit the piston and broke a piece off. Got a new unit. Checked the heads and found that the side that broke (pass side) had way too much wear on the valve guides. Take off the spring and the valves would wobble. This was only in one side. The other side was fine.