Rebuilding a 429-How can I get 400+hp/ 500 torque out of it?

[mtbx23]

My dad and I are rebuilding a 429 from a 67 Eldorado. I am a novice at building engines, but have a good knowledge of their workings. What can I do to get the most hp out of this type of engine? What should I do with the heads? What about using a crank from a 472 or 500? Any info would help..also where is the best place for O.E. or aftermarket perfomance parts?
Thanks.

[STDog]

My dad and I are rebuilding a 429 from a 67 Eldorado. What can I do to get the most hp out of this type of engine?

Normal stuff to increase HP. I don't know the 429 at all, but It's more effecient tht the 472 family that replaced it. parts for it are more difficult. There's basically zero after market for it, much like the 472 was a few years ago.

What should I do with the heads? What about using a crank from a 472 or 500?

Port the heads and intake. The more work you can do the better. Probably need custom made headers, as I doubt there's anything off the shelf. Cam again, will probably have to be a custom grind, from a stock core.

I don't know if you numbers are possible without lots of custom (read expensive) parts.

The heads, crank, and most other parts from a 472 family (500, 425, 368) engine will not work.

[Terrible One]

It may be cheaper in the long run to sell it and then grab a 472 or 500 and go from there

[STDog]

It may be cheaper in the long run to sell it and then grab a 472 or 500 and go from there

Unless you're restoring the vehicle. Not sure what kind of hit you get for internal, non-visible mods to the drive train. But yeah, if you not interested in keeping the 429 for show/personal reasons, the 472 would be much easier to modify.

Of course there's something to be said for being different, and if you've got the money and desire...

[Terrible One]

Ah yeah, didn't think about it being a show car, or him just wanting to keep in # matching anyways. However, if he plans for it to be a show car, he should already know that a lot of $$$ has to go into it, so all of these cutom 429 parts may not be too bad of a problem.

[mtbx23]

Hey thanks guys..the reason for the 429 is that its the only thing i have..the engine is in horrible shape (minus cracks so far) and i dont think i would get too much money for it anyway. Money is certainly an issue..but i am willing to pay the few extra bucks to put a few more horses in this thing. Any tips or info would help

[Terrible One]

Well are you wanting to keep the 429 so that it is numbers matching, or for any other reason? If not, just pay a couple or few hundred for a good 472 or 500 and enjoy the much bigger aftermarket, whilst spending less money.

[rockhog]

Well are you wanting to keep the 429 so that it is numbers matching, or for any other reason? If not, just pay a couple or few hundred for a good 472 or 500 and enjoy the much bigger aftermarket, whilst spending less money.


Terrible one is right on target here. Toss the 429 in the dumpster and go straight to a 472/500. More power and much cheaper to buld for HP.

[dave_brode]

mtbx23,

If you can find a 472 or 500 powered eldo, grab it and use everything to switch yours to the later engine. The trans will need to be swapped too, or just swap your trans' innards into any bop TH425 case. Realize that your '67 eldo trans has a switch pitch trans though. Only '67 Eldo and '66/'67 Toro had that feature. I would swap your stuff into a bop trans case to retain the s-p.
Dave



"]My dad and I are rebuilding a 429 from a 67 Eldorado. I am a novice at building engines, but have a good knowledge of their workings. What can I do to get the most hp out of this type of engine? What should I do with the heads? What about using a crank from a 472 or 500? Any info would help..also where is the best place for O.E. or aftermarket perfomance parts?
Thanks.[/quote]

[frankenstang57]

:evil: AARRRRGGGHHH!!!!! Not a '67! That's the reason I'm on this board right now. Lemme tell you about '67 429's. My buddy buys this hearse. '65 429. The tc had jumped and it didn't run. Put in a new timing set, it ran great! Well mostly, if you didn't take into account it burned about a quart of oil every hundred miles. Rings were gone, since the former owner used starting fluid on it in copious amounts to fire it up, while the tc was failing! :roll: Long story short, Dude: Hey do you think we could fix this in a weekend? Me: Sure, let's go find a 429 in the 'yard, rebuild it, and just swap the two. Dude: That's a great idea. Turns out, after investing about a grand at the machine shop, the '67 uses uses it's own valve train, has it's own oil pump, and the timing cover is completely different. I think he found all the rockers and the what not out of Canada someplace. It was really expensive. After swapping the two motor, I could never get the stupid thing to run just right. Then, for some mysterious reason, (I've been to PO'd about the whole thing to care why) it @#$#@ locks up. No idea why, yet... As far as getting more hp out of one of these, you'll spend far more than it's worth, that is if you could find the parts. Oh yeah, they make no go fast parts for 429's... Sounds like a 472 swap is instore for you! At least that's what I did. :evil:

[zenish]

if you scrap the 429 save the cool valve covers.

[mtbx23]

Thanks for all teh advice everyone..but despite your help im keeping teh 429...ill let you know how it turns out

[frankenstang57]

:evil: Good luck with that. Sorry about the rant, I'm just annoyed about the situation. Big thing with the 429 IMHO, is the oil pump. Take care in rebuilding it. I believe this is why my engine failed. FWTW, you should only have about 25psi running down the road. Cadillac has a very light spring on the OP bypass valve, and that is the specs. The 429 is a decent motor, but you're not going to get the same out of it as a 472/500. :evil: