Pontiac 6X heads and cam suggestions

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Ron Miller
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Pontiac 6X heads and cam suggestions

Post by Ron Miller »

I have a set of stock 1979 Pontiac 6X heads. I'm looking for suggestions on the valve job and some basic porting. Also would like suggestions for a Hyd roller cam & lifter combo. Will the stock valves hold up to a Hyd roller? This head package is going on a stroker 400 that will end up 461ci. This is a 4-speed car with 3:31 rear gear with power brakes. Would like a litte lope in idel but needs to have enough vacuum for the power brakes.

Thanks for looking,
Ron Miller
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Re: Pontiac 6X heads and cam suggestions

Post by PRH »

There is some good porting info for Pontiac heads in the book “how to build max-performance Pontiac v-8’s” by Jim Hand.
Somewhat handy with a die grinder.
gmrocket
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Re: Pontiac 6X heads and cam suggestions

Post by gmrocket »

If it has the 30deg seats on the intakes, get rid of that
pdq67
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Re: Pontiac 6X heads and cam suggestions

Post by pdq67 »

Dam, I remember when a 389" tripped Goat engine was King!

Glad you are playing with Pontiac V-8!

It's kind a like the old 401 Rambler V-8, out of site, out of mind!!!

pdq67
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Re: Pontiac 6X heads and cam suggestions

Post by pastry_chef »

Pete Mccarthy porting DVD
http://www.petemccarthybooks.com/index. ... NG_DVD/198

I've never used stock valves.

What compression ratio will the engine have?
If the engine will be around 9.5 CR maybe a cam like this:

Howards hyd roller (Harold Brookshire lobes).

Intake - HR2353683
288 adv
235 @ .050
158 @ .200
0.368 lobe lift

Exhaust - HR2413750
296 adv
241 @.050
164 @.200
0.375 lobe lift

112 or 114 LSA offer decent idle and vacuum.
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Ron Miller
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Re: Pontiac 6X heads and cam suggestions

Post by Ron Miller »

Guys,
Thanks for the replies. 8) I'm hoping the compression ratio will end up around 9.5. Another question about installing a roller cam in this Pontiac. Will the lifter bodies clear the valley pan? If not, is there a modified valley pan available? Also, what do I use for a cam button?

Thanks Again,
Ron Miller
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Re: Pontiac 6X heads and cam suggestions

Post by Firechicken »

The valley pan may or may not clear roller lifters. If not, you can modify it with a ball peen hammer or there are several aftermarket ones that will clear.

No button needed on a Pontiac. Cam is positively retained at the front of the block.
Ron Miller
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Re: Pontiac 6X heads and cam suggestions

Post by Ron Miller »

Firechicken wrote: Sun Sep 20, 2020 3:16 pm The valley pan may or may not clear roller lifters. If not, you can modify it with a ball peen hammer or there are several aftermarket ones that will clear.

No button needed on a Pontiac. Cam is positively retained at the front of the block.
I currently have the heads only, no short block. This is my first Pontiac valve job and possibly a short block build. Anybody know what the valve job angles are or need to be?

Thanks for the reply,
Ron Miller
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Re: Pontiac 6X heads and cam suggestions

Post by Firechicken »

Check your heads for a secondary stamping on the side boss.
6X-4 is around a 92cc chamber
6X-8 is about 101cc.

For a mild build with factory heads and .450ish lift at the valve, keep the 30 deg. Intakes.
cpmotors
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Re: Pontiac 6X heads and cam suggestions

Post by cpmotors »

Intake cutter 069B, Exhaust 005B has worked for me several times.
Howards 94345 Timing set works well
Valley tray is usually making contact or close, I separate, clean, trim and weld back together.
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pastry_chef
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Re: Pontiac 6X heads and cam suggestions

Post by pastry_chef »

Butler has many aftermarket style valley pans with better clearance.
https://butlerperformance.com/c-1234757 ... -pans.html

They also carry these very nice lifters.
Johnson High Performance Hydraulic Roller Lifter Set, Short Travel JLI-ST2112OPR-16
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