66 Tri-Power Lookin for a 66 tri-power.......anyone know of any? Preferably on the east coast. Email: Fitchfan1@aol.com https://web-cars.com/phorum//read.php?3,32316,32316#msg-32316 Mon, 05 Oct 2026 14:02:55 +0000 Phorum 5.2.23 https://web-cars.com/phorum//read.php?3,32316,36791#msg-36791 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36791#msg-36791 Charlotte Pontiac GTO Forum Fri, 14 May 2010 03:17:27 +0000 https://web-cars.com/phorum//read.php?3,32316,36434#msg-36434 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36434#msg-36434

First, a 455 has the same deck heigth as the 326, 350, 389, 400, 421, and 428. That said, the head is the critical factor. Heads from 61 to 64 have different water passages, a different bolt pattern, and a different angle where they meet the intake than do the 65 and later heads.

Therefore, what most people want is the popular 65 or 66 tripower to fit the improved and readily available 65 up heads. A 65 or 66 tripower will bolt directly to the 65 to 71 Pontiac heads. However, starting in 72, Pontiac has an extra exhaust crossover port in one of the heads. The 6X head is a mid-70s head and has this extra port. The 65/66 intake will not cover this port. There is no special intake gasket to accomplish this. The force of the exhaust is too intense for a gasket to stop. Best method is to have a machine shop fill this extra port while you are having the head work done. At least one customer filed this port while the head was on the car, using JB Weldand reports no problems. I am much more comfortable with the first method.


Many thanks to www.pontiactripower.com for the information above.]]> gto455tripower Pontiac GTO Forum Tue, 25 Aug 2009 17:55:57 +0000 https://web-cars.com/phorum//read.php?3,32316,36433#msg-36433 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36433#msg-36433
Honestly, if you do a search on the internet you will find serveral articals that refer to exactly what you want to do. If I have a bit more time later I will post links.

Note: my block is a 1973 Block out of a Grand AM my intake is from 1966.]]> gto455tripower Pontiac GTO Forum Tue, 25 Aug 2009 17:41:45 +0000 https://web-cars.com/phorum//read.php?3,32316,36087#msg-36087 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36087#msg-36087
Quote
getreeltoo
Has anyone installed a 66 Tri-Power on a 72 455 and if so what type of intake gaskets did you use? or can this even be done? The problem that I am finding is that the heat riser port on the intake passenger side doesn't match the heat riser port of the head.

Johnny

You're going to need a tri-power intake manifold that will bolt onto a 455 block... don't know if those exist, but if they do they're going to be specialty orders.]]> gtojack67 Pontiac GTO Forum Tue, 17 Mar 2009 13:22:43 +0000 https://web-cars.com/phorum//read.php?3,32316,36083#msg-36083 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36083#msg-36083
Johnny]]> getreeltoo Pontiac GTO Forum Mon, 16 Mar 2009 23:11:54 +0000 https://web-cars.com/phorum//read.php?3,32316,36031#msg-36031 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,36031#msg-36031
I also have the chrome valve covers for that engine.

Ray Overstreet
Austin, Texas]]> rayo1949 Pontiac GTO Forum Sat, 24 Jan 2009 04:50:39 +0000 https://web-cars.com/phorum//read.php?3,32316,34852#msg-34852 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,34852#msg-34852
Tim]]> Tim MacEntire Pontiac GTO Forum Thu, 21 Jun 2007 17:41:46 +0000 https://web-cars.com/phorum//read.php?3,32316,34090#msg-34090 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,34090#msg-34090 robbie Pontiac GTO Forum Sat, 25 Nov 2006 15:30:54 +0000 https://web-cars.com/phorum//read.php?3,32316,32321#msg-32321 Re: 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,32321#msg-32321 ONE BOLT ON READY ONE NEEDS A REBUILD.
CALL ANY TIME..
845 656-2510
IN NY 12569
PHIL]]> Toyswedo Pontiac GTO Forum Sun, 09 Oct 2005 01:56:48 +0000 https://web-cars.com/phorum//read.php?3,32316,32316#msg-32316 66 Tri-Power https://web-cars.com/phorum//read.php?3,32316,32316#msg-32316
Email: Fitchfan1@aol.com]]> Lookin4A66 Pontiac GTO Forum Wed, 05 Oct 2005 14:34:06 +0000