I'm ready to order my pistons for the long-rod rebuild. My block and head have never been cut, and I'm only planning on a clean-up cut for a good gasket seal.

That said, should I expect to have to machine the piston to lower the compression - or just drop them in and go?

I'm looking for an SCR that I can run pump gas on - it's okay if that's premium, and I'm using thermal barrier coatings to lower the chance of detonation and will be applied to the head & valve-faces too. That's the plan anyway - always open to suggestions. Will be using OG #346 cam.

I'm asking because I would prefer Wiseco apply the thermal barrier coating, then to sub it out. If machining is expected, I'd want the pistons raw from Wiseco.

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

You will need to check that the valves are not hitting the eyebrows in the pistons if you are running oversized valves. Mine had to be enlarged.

You need to CC the head and then try and calculate a CR. my uncut block had the pistons down the cylinder about .017 (If I remember correctly) Problem was my block was off .020 front to back and had to be cut that much to square things up. So I ended up with near zero deck.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Planning on 1.70 & 1.45 valves Rick - still a concern?

On a related note, will laying back the intake pocket improve flow here? Has anyone done it?

TY for your reply!

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

Those valves should be fine, but I would still check it w/cam installed/degreed and with play dough. Just set the head on with no gasket and 4 bolts and run it around. If you get any resistance, stop, so you do not bend a valve if it hits.

With the 346 cam, you will want no more than 10:1 comp, and 9.5 would be safer for pump premium. I would degree it at 100-102. You will likely want to use a thick head gasket and not cut the block any more than needed.

Lou

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Home of Slant6-powered fun machines since 1988

Lou - thank you, I much appreciate the insight.

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

My valves were 1.76, 1.46.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Rick - then the margin is probably too close for mine. Safe bet is to buy the pistons uncoated, and deal with the coatings after the pistons are measured in the hole. Much help today gents.

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It