Twisted wedge heads on stock 5.0 pistons?

[frdnut]

My brother has a low mileage 1987 5.0 that he wants to build..He was thinking of bolting on a set of twisted wedge 170 heads..The info on the trick flow website is sort of contradicting..It says the different valve location gives you extra clearance up to .550L and then in another spot it says you need the twisted wedge specific piston?

[Applejack]

Has he called Trick Flow?

[Lukesportsman]

Do not take this as gold, but how I always recall them advertising it was that you could run it up to .550" without a piston swap, but after that you'd need TW relieved pistons.

If I recall correctly, the 87' had forged pistons before the swap/change over to HE pistons? I seem to recall them being a 1 or 2 year specific shortblock with relieved pistons, but I would always (as I'm probably preaching to choir) clay them before install. I acknowledge your just trying to minimize surprises, but needed to add that caveat.

[ScottsGT]

You're good until you hit .550 lift. That includes added lift if you're running 1.7 rocker arms. Still check though.

[frdnut]

Originally Posted by Applejack

Has he called Trick Flow?

No not yet..We were hoping to hear from some people who have actually done the swap for some first hand experience..

[TXMAG]

Confirming what ScottsGT said - You should be fine on the stock piston up to .550 lift. Regardless you should always check your PTV clearance.

In regards to the forged pistons:
85 4v models
86-91 all motors
92 early-mid year motors
Late 92-95 had the hypereutectics

[Z06killinsbf]

You'll be fine like said, 86 was the last year of the non-valve relief pistons. The TWs are also the only 2.02 head you can run without notching the pistons. Also, you can form a DIY piston notcher with left over junk parts if you do need a little extra room.

[65ACodeCoupe]

Originally Posted by frdnut

No not yet..We were hoping to hear from some people who have actually done the swap for some first hand experience..

I have the TW 170's on my stock piston 289 with a Comp Cams XE266HR ( 0.544 int./0.555 exh; BTW great combo it pulls to 6000 rpm ). Even with the heads milled about .040" there was plenty of room. You should still check PTV clearance, though.

[jdub]

Duration is more important than lift. When the valve is at peak lift, the piston is way down the cylinder. I am afraid you are going to have to take your chances with the parts and check PTV clearance unless you can verify someone has ran the exact same combo, including cam and any milling of the deck (5.0 pistons are about .012 down the hole). And even if they have, you still want to check.

But yes, people have had good results with TFS heads on stock 5.0 blocks without altering the piston. It can be done. You just need to use your head, which I am sure you and your brother will.

[frdnut]

Thanks for the info guys..Not sure what he wants to run for a camshaft yet.It will be a hydraulic roller of some sort and he is old school and definetely wants some lope at idle..The motor will be carbed and going into his 67 fastback.

[sportsroof69]

I don't know how they get away with saying .550 lift, but they always have. As stated above, duration plays a larger role in P to V contact. Always always always check the clearance. I ran TW185s on a stock 351 bottom end with several different cams. I think the largest was an XE274H.

[Z06killinsbf]

Use those heads and a Trickflow Stg 2 cam, that will give him the thump he's looking for. And it'll run great, don't let him be talked into a Ford "letter cam" unless y'all get it for a song.

[ScottinVA]

Originally Posted by jdub

Duration is more important than lift. When the valve is at peak lift, the piston is way down the cylinder. I am afraid you are going to have to take your chances with the parts and check PTV clearance unless you can verify someone has ran the exact same combo, including cam and any milling of the deck (5.0 pistons are about .012 down the hole). And even if they have, you still want to check.

But yes, people have had good results with TFS heads on stock 5.0 blocks without altering the piston. It can be done. You just need to use your head, which I am sure you and your brother will.

Jdub is absolutely right here by saying duration is more important. They throw out that 550 but its just a general rule of thumb. I'm running the XE284H and have tons and tons of clearance. We'll be stepping up to something around 600 lift with those same heads soon.

[70BOSS302]

The above post is correct about lift not being important because the piston is way down in the bore at max lift- its the duration. I don't know why tfs even uses lift as a factor except most cams at xx lift have a similar duration . I called tfs and asked them about this and they stated a tfs stage 2 cam is as large as you can go on a factory style piston. You cam always cut the piston in the block using a lindy tool-much better than isky

[jdub]

The TFS Stage 2 cam seems like a good cam for a hot street car. I would be using it but since I have the proper valve reliefs I decided to go with a slightly more aggressive Howard Cam.