Sounds like some guys had some fun over the weekend Bjorn, Brett, and Q. I picked up that parisienne for that 455 over the weekend for $500.00. What a steal the car runs great no smoke at any RPM and idles like a dream. How do I find out what kind of tranny is behind the 455? Also would the rear gears be of any use in my bird? seems fairly low in the parisienne. The gears I have now are 256s.

Thanks Jag :p

It's probably a TH 400 tranny, and the gears will most likely be 8.5" rather than 8.2" (For us south-of-the-border types, what's the Parisienne look like?)

Q

Hi Q
Have you ever seen a beached whale, well this is bigger and browner and uglyer.
PS I wouldn't mind hearing some of your tweeks for the 455.

Jag

Ewwwww ... I had one of those once, but it wore the name "Belvedere."

Definitely gonna have a TH400 and 8.5" gears. The trans will fit your Bird, but not the gears.

As for 455 tweaks: That depends on the budget, and what you want the car to do. Let's assume you want to transplant the motor "as-is," and that you have the stock '74 heads (which implies the stock compression ratio and valve size). Let's also assume this is a "daily driver."

IMHO, the most bang for the buck will come from swapping the timing chain for a Cloyes double roller set with a +4 degree setting. Don't forget to re-set your ignition timing after the swap!

If you also get some headers or long-branch manifolds, the next low-budget tweak would be to swap the 1.5 rocker arms for 1.65 units on the exhaust valves. (This will work and won't require you to do any messing wth the push-rod holes.)

Carb jetting and probably a little work on the mechanical advance will be a good idea here. Keep the Q-Jet. Holley/Edelbrock carbs are good, but for a stock or almost stock motor, the Q-Jet is hard to beat.

These mods will give you a good boost in low and mid-range torque and power. You'll notice this a lot if you do plenty of daily driving. You may not notice that much change at the track, except an improvement in your 60 foot times but a slight drop in the MPH thru the traps. ET could be slightly quicker, but not necessarily.

Now, if you're going to tear down the motor and go for a re-build, then the myraid of possibilies wouldn't fit into this space.

As usual, this is just one guy's opinion(s)

Q

Hi Q
I'm not sure what to do. Iv'e got those 670 heads. I don't know if this would be an improvement over the stock ones but I was thinking they might be a good change. Change the cam to maybe an 068 - 067 - 744 pontiac, put a edelbrock performer RPM intake on it and use either the factory carb or an after market edelbrock. I don't really want to go after the bottom end if it does'nt need it. Does this sound like I'm on the right track or am I sniffing glue?

Your Bud Jag

The 670's on a 455 is not Glue territory, but you'll be sniffing octane boost or racing fuel. (I had a set of 670's on my 455. While they are great heads, and made a monster out of a ... well, a monster. They are too much to run on good ol' pump gas. I am MUCH happier with 7K3 heads on my 455 now.)

All the other mods, like the 068 cam, the Performer RPM and the upgrade carb are also good improvements, and they would fall into the mid-range budget stuff. You've got to go with better exhaust flow if you do all that the the top end, though.

If you go with the 670 heads, you'll HAVE to get into the bottom end to add 4-bolt mains and probably some better rods. Keep those heads handy only as a last resort! Find a set of 96's, 7K3 or 4X, 5C or 6X heads instead. You'll be much happier in the long run, IMHO.

Q

Thanks for your help Q!!
Is the stock heads any good for anything. And what type of edelbrock carb whould you go with.

Thanks Bud Jag

Depends on which heads they are. Stock 455 heads from 1974 are 4X-1H. 4X heads are good heads, and the 1974 4X heads from a 350 or 400 are often used as the starting point for a 455 build-up. The problem with the 455 4X-1H heads is that the chambers are rather large (114 cc), giving pretty low compression and the exhaust valve is "small." To increase the compression and get more output, you have to reduce the chamber volume. Pontiac achieved this by having heads with different combustion chamber sizes. A "good" 455 chamber volume is about 95 cc. To compensate, you can either mill the heads down, or swap in a set of heads with a closer chamber volume. Or, you can get the intake valve to close a little sooner.

As for carb recommendations, that's a tougher one to answer. I only know Holley and Rochester, and most of my Holley experience has been with two at a time. My recommendations for a single 4 Bbl. carb is always to go with the Rochester. Something from 1968, 1969 or 1970 like the 262, 263 or 264 carbs from those years, since they are more plentiful, and every bit as versatile as the hard-to-get carbs.

Q

Jag, great news! Way to score!

Yes, I'd do a little tweaking to the top end (especially if you plan on doing the intake and carb). I'd say you'd want a 750 -800 cfm carb. If the stock Q-jet is in good shape, then keep that for a while, they are nice performing carbs.

But the most popular ticket for the 455 is usually the 6X heads (6X-4 is prefered) they alow you to use pump gas and can be modified for great performance. But then again, many heads can always be "Made Better"

So for now, see if you can clean her up, drop the engine and tranny in, and enjoy the summer. Sel some parts from the car to save for the work to do over next winter?

Most of all, just enjoy her!

Thanks for the update!
Brett - 67 Drop Top 455!

Hi Guys
First off Id like to thank Q for all his help which he has given me alot. Second these toys we have are so much fun and for someone from Alberta Canada being able to talk to someone from Los Angeles or Huston texas about our passion is extraordinary. Brett I appreciate your support and its guys like you that give us the drive to do more.I wish I was cruising with you guys one the weekend. I'm a pipeline welder here and thing are pretty busy right now so I might be in and out a bit. Once I get some more info I'll be back in touch.

Have a good one
Jag

Hey, that's what it's all about here! Just sharing what we have learned (we hope we learn from our mistakes) Or if your Like Q, you just absorb this info like breathing air... Lol...

If you ever get down towards Seattle, please let me know, and we'll do that week-end cruising! Bjorn was here before, and will be again the first week of Aug. I usually try to get a few of the local Firebird guy's together for a cruise, or just an excuse to bring the cars out, and talk birds. Same with Hugo in the SF Bay Area, and Bjorn in Houston, Q in LA etc...

Last few times people from the list came out this way, I managed to get about 5-10 birds together at least. Last time I was down to San Fran, Hugo got I think 17 birds together... that's what it's all about!

Hope to catch up some time!

Brett - 67 Drop Top 455!

Hi Guys
I got some info from the 455. The heads are 4X And the carb is a Quadrajet . The numbers on the carb are 7044262 and under that is 1214. What I would like from this engine is about 350hp and fairly torkey. Any Ideas?

Thanks Jag

What's your budget?

Q

Here's a site that may help, or you should read anyway for good info. It will give you the basics of the what and why.

http://home.stny.rr.com/pontiacs/heads.html

Then go here to check out some Engine Dyno simulations and you can get a good idea of the combination, and future potential.

http://www.pontiacwarriors.com/dyno/dynosims.htm

Lots of ways to go with the right cams etc!

Brett!

Hi again
I don't have any budget Q. I don't want to spend huge dollars but also don't want to be beat by any jap crap either. I looked on the heads again for more numbers but all they say is 4X. You were telling me before that the chamber size varies from 94cc to 114cc. If these heads are 114cc that means it has 8/1 compression. You were recomending 9/1. I figured out what the 670 heads woul be on the 455 and it worked out to 12.5/1 way to high. Is it possible to port the 670 heads to 95cc or 100cc which would bring compression down to about 9/1? Brett I read that site on heads you gave me and was very interesting thanks. I allready had pontiac warriors dyno sit from Q and looking threw the 455 dynos they seemed to kind of talk down the 4X heads.I guess if these 4X heads had 94cc chambers They would be pretty good. I don't mean to ramble on but I'm just trying to do my homework right. Thanks for your help guys!!!

PS My buddy and I were in lethbridge a couple of weeks ago doing some crusing in his 67 GOAT 389. We were sitting at the lights when a little red Jap crap with the back fin and the loud sewing machine mufflers wanted to play. We left the line all rubber of course threw first gear and believe it or not the sewing machine was right beside us untill we hit second and it was all over but the crying. We stopped at the next set of light and mr sewing machine would'nt even look at us Ha HA Ha. I guess we chalked one more notch for the pontiac belt that night.

Jag

They are most likely the 114 cc chambers. It will cost way less to mill those heads down than to open up the 670s.

I've only seen one set of #670 heads opened up like that, but they were opened to 80 cc, not 95 cc. And it's all done in the chambers, not in the ports. The porting on them adds more bucks to the equation.

Milling heads takes about .004 per CC. To get the 114's down to 95 will take a lot of milling. I would not recommend milling heads more than .060. That will get you down to about 99~100 cc. Also, you'd want to do a valve job and maybe make sure you had good guides and springs, new seals, etc. Pretty soon, you'll have a few hundred dollars in those heads. You probably could find a set of heads already worked and rebuilt for about that much. Or, you could find a set of stock heads with the big valves and the right chambers that just need a valve job.

And, like I said above, you'll want a good 4-bbl manifold, a good Q-Jet, a cam and good exhaust manifolds or headers. Believe it or not, you could use all stock parts and get more than your goal of 350 HP on 9:1 compression.

Q