Promaxx Heads
#72
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Joined: Oct 2002
Posts: 2,055
Likes: 91
From: Bowling Green, Kentucky
Finally did dyno the engine. Thanks to Ray at R&R Motorsports. I will post the sheets. Ended up about 530 HP and lots of low RPM torque. I made the mistake of not buying a new carb and just using the old one so that compromised my ability to tune in the idle. I’m not sure anything significantly more going to happen on the big end.
i was really nervous this being my first build but it didn’t scatter and it looks like I built a good engine. No leaks. It went very well. I’ll post more data so that it can help others with their build choices.
i was really nervous this being my first build but it didn’t scatter and it looks like I built a good engine. No leaks. It went very well. I’ll post more data so that it can help others with their build choices.
#74
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Joined: Mar 2020
Posts: 845
Likes: 506
Congrats on the build Doc. Looks like we share a few of the same parts. Promaxx heads, Canton oil pan, and MSD distributor.
What material are your freeze plugs? The one on the back of the block doesn't look to be brass.
SB, if you're asking about my belt alignment problem, there wasn't one. The problem was me. I was trying to use too long of a straight edge that was causing me issues. I bought a piece of straight 3/8" rod and placed it inside the pullies and everything lined right up. I then placed it flat against the back of the pullies and once again, everything was good. Chalk it up to user error.
There was no problem with the Promaxx heads and OEM accessories installation.
What material are your freeze plugs? The one on the back of the block doesn't look to be brass.
SB, if you're asking about my belt alignment problem, there wasn't one. The problem was me. I was trying to use too long of a straight edge that was causing me issues. I bought a piece of straight 3/8" rod and placed it inside the pullies and everything lined right up. I then placed it flat against the back of the pullies and once again, everything was good. Chalk it up to user error.
There was no problem with the Promaxx heads and OEM accessories installation.
#75
Last edited by articfriends; 10-20-2025 at 07:18 AM.
#76
Finally did dyno the engine. Thanks to Ray at R&R Motorsports. I will post the sheets. Ended up about 530 HP and lots of low RPM torque. I made the mistake of not buying a new carb and just using the old one so that compromised my ability to tune in the idle. I’m not sure anything significantly more going to happen on the big end.
i was really nervous this being my first build but it didn’t scatter and it looks like I built a good engine. No leaks. It went very well. I’ll post more data so that it can help others with their build choices.
i was really nervous this being my first build but it didn’t scatter and it looks like I built a good engine. No leaks. It went very well. I’ll post more data so that it can help others with their build choices.
#77
Registered


Joined: Aug 2019
Posts: 1,225
Likes: 415
From: BC
Congrats on the build Doc. Looks like we share a few of the same parts. Promaxx heads, Canton oil pan, and MSD distributor.
What material are your freeze plugs? The one on the back of the block doesn't look to be brass.
SB, if you're asking about my belt alignment problem, there wasn't one. The problem was me. I was trying to use too long of a straight edge that was causing me issues. I bought a piece of straight 3/8" rod and placed it inside the pullies and everything lined right up. I then placed it flat against the back of the pullies and once again, everything was good. Chalk it up to user error.
There was no problem with the Promaxx heads and OEM accessories installation.
What material are your freeze plugs? The one on the back of the block doesn't look to be brass.
SB, if you're asking about my belt alignment problem, there wasn't one. The problem was me. I was trying to use too long of a straight edge that was causing me issues. I bought a piece of straight 3/8" rod and placed it inside the pullies and everything lined right up. I then placed it flat against the back of the pullies and once again, everything was good. Chalk it up to user error.
There was no problem with the Promaxx heads and OEM accessories installation.
#80
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Registered

Joined: Oct 2002
Posts: 2,055
Likes: 91
From: Bowling Green, Kentucky
This is a snap from video of the best pull with not my carb was the best Hp. Was a Willy’s carb. I will post sheet in a few when I get to office
Last edited by SkiDoc; 10-23-2025 at 04:34 AM. Reason: Add text





