[H Larson]

Thinking about buying exhaust manifold for a ´66 GTO. From the PY catalog I am choosing between RPE650 ´67 HO or the RPE650H. Any suggestion which one would be the best choice? I am looking for performance increase without using headders. Any input would be appreciated.

[Andre]

Go with the HO manifolds. They are well made, and work well.

[eaglesan13]

I would also go with the HO manifolds. But I would also replace the front metal brake lines with the HO ones, otherwise the drivers side one will sit right next to the exhaust manifold. The factory routed the HO lines outboard of the frame rail for a reason. JMO

[H Larson]

Did not know about the HO brake lines. Thanks for the information. Appreciate your input.

[H Larson]

Originally Posted by eaglesan13

I would also go with the HO manifolds. But I would also replace the front metal brake lines with the HO ones, otherwise the drivers side one will sit right next to the exhaust manifold. The factory routed the HO lines outboard of the frame rail for a reason. JMO

Just a quick question. Should I use brake lines "1967 Power Drum RA/HO"? (PY online catalog) Power drums on the ´66.

[66GTO Jim]

Hey Hans,

I changed my 66 389 to 67 HO Manifolds. In addition to teh above posts, you also have to get the 67 HO wiring harness, positive battery cable and special heat shield tube. In 66, the wiring harness and the positive battery cable run through a different style heat shield tube that is mounted between the ports of the "log" exhaust manifolds on the driver side. With the 67 HO manifolds, there is no space to run the wires. So the wiring harness runs to the front of the engine across the top of the engine between the head and intake manifold and down the front of the engine and back under through a different small heat shield tube that is connected to the motor mount. The positive battery cable also runs through this tube and goes to the starter with the other wires. MAKE SURE you keep the battery cable away from the exhaust manifolds as this is a serious fire hazard if the positive battery cable cover burns through and grounds to the manifold or engine.

All the needed parts are available from our PY Sponsor. Jim

[H Larson]

Thanks for all that information Jim. This forum is one great place for information. I will go thru PY catalog and order all parts needed. Thanks again.