CFM Tech throttle body

**Slow1500** · 06-18-2008, 09:56 PM

I'm sure some of you may have one or at least heard of CFM Tech products. I just installed the bored throttle body on my 4.3 today and the gains are well worth it. Of course the truck will never be fast(unless I send it to Nelson Racing..ha) but the throttle response is improved a great deal as well as some increased top end pull(~3k-5k+ rpm). It only took 30 min and that was taking my time. I got a $5 tb gasket from autozone just for the assurance of no leaks. Just unhook your battery, take off intake tube, the few bolts holding it on as well as the IAC valve and TPS wires, and lift it off. Easy.
They make bored tb's for the '96+ vortec 4.3s, 5.0s, and 5.7s.

For the 4.3 the stock i.d. is ~ 71mm. The bored tb is ~73.1mm. Any larger and a few areas would be too thin and brittle(being cast aluminum). That small increase, as well as a new throttle blade, makes a decent difference.

**no0b123** · 06-19-2008, 01:01 AM

How much was the part? And what exactly did you replace?

**Slow1500** · 06-23-2008, 10:32 PM

Sorry, meant to put the link. The whole throttle body was replaced.

http://marine-performance-parts.com/...3vortecv6.aspx

**no0b123** · 06-27-2008, 07:24 PM

Is your 5 speed Automatic transmission? I have the same truck (06) but I think mines a 4 speed. Anyhow, how was the performance gain after this mod? And how fast does your truck perform now that you have several mods? Which was the most beneficial?

**Slow1500** · 06-27-2008, 09:55 PM

5 speed manual. The best mod so far is the throttle body...made the biggest difference in throttle response/acceleration, for sure. Next would either be the K&N kit or the Hypertech. I mean this truck is not fast but is more fun to drive with the mods. It doesn't feel as choked down anymore. Headers are next and should provide the biggest gains.

**no0b123** · 06-28-2008, 05:40 AM

Manual transmission, gotcha. Pleast post the performance gains of new headers in the future. About the throttle body, does it really increase horsepower or just throttle responce. And how exactly does the core return work out? What do you get with this purchase and how did you install it?