# Custom 472 Stroker Questions



## jtwoods4 (Dec 22, 2011)

I just bought a 69 GTO that has a custom built 472 Stroker (originally 455). The sellers did not know many details about the engine.

The seller claims the engine makes 500 HP and was setup for the quarter mile running 11 seconds. The car does run really good. This is all the info I was able to get from the seller. It is pretty vague:

Balanced and Blue Printed
Stroker Kit
Crower Rods
Fordged Crank
Fordged Pistons
Stainless Steel Valves
HJydraulic Cam (specs unknown but very rough idle)
*Ram Jet Pontiac Heads*
Holley 850 Double Pumper
*Offenhauser 360 Intake*
8 quart oil pan
Hooker Competition Headers
Flowmaster Exhaust
3 inch pipes


What are Ram Jet Pontiac Heads???
Is the Offenhauser 360 Intake any good?

Given the setup, what can you guys tell me about this engine? Let the comments rip!

Engine Image 1
http://farm8.staticflickr.com/7153/6625763869_3e6f88d67a_b.jpg

Engine Image 2
http://farm8.staticflickr.com/7015/6625765427_c0a64b274a_b.jpg

Engine Image 3
http://farm8.staticflickr.com/7023/6591707061_60e507be7e_b.jpg


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## Rukee (Feb 8, 2007)

Nice clean install, I like it!! :cheers


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## teamwoody72 (May 23, 2008)

My recommendation is to sell me the motor...LOL..Sounds like its gonna be a beast


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## kilkm68 (May 5, 2011)

Beautiful clean engine! I've got a 474 stroker thats really quick and doesn't have the carb, headers or msd ignition you have! I'll bet that's a really fast car, what transmission do you have?


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## BearGFR (Aug 25, 2008)

jtwoods4 said:


> What are Ram Jet Pontiac Heads???
> Is the Offenhauser 360 Intake any good?


1) Never heard of such terminology myself, the heads in the photo look like regular Pontiac D-ports. If you can get the codes off them, we can help id them. We need 2 codes: first the date code which will be 4 characters and located either here:









or here:









and the head casting code which will be here:









2) The Offy 360 is a decent dual plane manifold. A lot depends on the rest of the engine and how it's used. Folks who have put in lots of time testing different manifolds have usually found that on the street, nothing does better than a properly prepared factory iron intake, especially if it's been port matched and has had some of the casting 'bumps' in the runners removed.
Single plane intakes are going to "hang on" into higher rpms at the expense of not making as much low end torque.


Depending on which cam your engine has and how the rest of it was built, 500+ horsepower is very believable.

Bear


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## geeteeohguy (Feb 2, 2008)

Man, that mill must have a 3/4 race cam and a full house port job!!!


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## Instg8ter (Sep 28, 2010)

only thing it won't pass is a gas station.....believe me i know... Nice clean looking engine bay. numbers sound about right for the parts.....if it runs good drive it and see how you like it's manners, an 11 second car set up for the strip may be a bit rowdy on the street, all a matter of how you plan on using the car....:cheers


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## jtwoods4 (Dec 22, 2011)

Thanks for all the nice comments guys. I'm going to find out what the casting numbers are on the heads. The engine is definitely a little rowdy When driving in traffic. Clutch and gas pedal have to be released just right to have smooth starts. It is definitely a fun car to drive. I will post the head casting numbers in a couple of weeks when I get back in town. On a side note I have another 400 block that I want to do a build up on this winter. I plan on balancing and blue printing the engine. My goal is to make a quick reving, hi winding 400 that will really snap your neck from red light to red light. I am currently reading engine build up articles for pontiac 400s and trying to select the heads, intake, Cam, etc. If you guys have recommendations I would love to hear what you have to say!


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## Rukee (Feb 8, 2007)

Don't be sold on high rpm's, Pontiacs make huge torque down low, unlike a chevy that needs the rpms to make power. I have all forged & balanced parts and never turn over 5,000rpms.


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## jtwoods4 (Dec 22, 2011)

What set up do you have on your engine? What are all the parts specs?


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## Rukee (Feb 8, 2007)

Everything is stock except forged pistons .060" over. Other then that it is a stock balanced Tri-Powered 389. Sounds great, check out my burn-out videos in my sig.


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