mrestrictrplate

iTrader: (2)

Hello. Doing twisted wedge heads on my other 87 L98 Iroc. Anoyone use TW Heads on a 350. Any cam reccomendations? The heads are ported and is a roller shortblock with 1 5/8 headers. Intake is Tpi at the moment but will have a stealth ram with the twisted wedge heads. 700r4 2400 stall and 3.23s Thanks Chris

mmadden55

Trick Flow? I have recomend them highly I was running a mild comp cams roller, however the heads are good to go with any roller mild enough to run on the street.

Twin_Turbo

iTrader: (25)

Yes, me (G1s) on several engines. I have 4 sets of them. They are excellent once you know how to set the valve train geometry right and take the time to do so. The stock springs however are junk IMO

mrestrictrplate

iTrader: (2)

Any recommendations for a cam with these heads? They are ported but I dont know flow numbers. Thanks Chris

TTOP350

iTrader: (8)

Would also bump the headers up to 1 3/4

mrestrictrplate

iTrader: (2)

I know I need 1 3/4 headers. Money is tight in the winter, using what I have for now.

Twin_Turbo

iTrader: (25)

these are the correct rockers btw, crane 11750



Runs fine on 1-5/8 primarkies, they are d port exhausts. No need for 1-3/4 unless your exhaust port requires that size.

BadSS

There are G1 and G2 Twisted Wedge heads. The G1s have 13-degree intake valves and are limited in cam size to 230-degrees duration at .050”, 0.530 lift, on the intake side with a 110 spread when running standard flat-top pistons (per TFS tech papers that came with the heads). Tighter lobe spreads decrease piston to valve clearance, so you could run a little more duration with a 112 or 114 spread. As others have said, making sure you have the right length pushrods for proper geometry is critical. Even when as good as it gets, the geometry is a little whacky and will give a little more than normal valve guide wear, but it’s not that bad (I ran a set for over 20,000 miles with no more than typical wear that I could see). The limited cam size (without running custom pistons that were available then), people running improper valve geometry,,, and with some of the G1s having faulty K-Motion springs gave them a bad rep.

Here’s a write up on my old 355 IROC with G1 heads swapping a fully ported TPI/SLP combo for a StealthRam.
http://www.superchevy.com/how-to/030...hird-gen-iroc/
I later swapped the HSR for a FIRST – it ran near identical times, but the FIRST was much more responsive and brought the shift-points down from 6400/6200 to 5800/5600 (218/228-110 flat tappet). For a “driver”, I preferred the FIRST intake, but the HSR was much easier to launch and would have been my choice if I were more interested in racing the car than driving the car. Still, once I got the tune right on the HSR it wasn’t what I'd call unresponsive – I’d compare it’s power band to a good dual plane carbed intake in the lower RPM range and a good single plane in the upper end.

If you have the G2 heads, they have a 15-degree valve, not as hard on the guides, and while I’d keep the cam limits to that of the G1 heads, I do believe you can run a little more duration. However, on a street driven 355, I’d keep it under 230 degrees on the intake and no tighter than a 110 spread anyway. Regardless of G1 or G2,, make sure the geometry is a good as it can be,,, and if you push the cam limits, I’d consider checking piston to valve clearance a MUST – many didn’t and paid a hefty price.