I found one available for less than 1k, supposedly working when removed from a GTO. Original heads, no intake. What would be the cost differences vs rebuilding a '68 400? Would the increase in power be worth it?

428 pistons will be more expensive & harder to find, what heads are on the 428? If it has big valve heads it would be worth building, ALOT of the '69 428 engines were the small valve variety, do your research!

Steve

tinindninkc ,
Thanks for the reply. The seller states it is out of a '69 GTO Judge, but I have my doubts (on line reasearch reveals that is a very rare post factory dealer addition). It's probably a big car engine with the small valves. I think I'll stick with my 400 - parts are readily available and I think I can get good performance out of it.

I would ask for the head code and block code, but sounds like and expesive risk. Could just use that 1K twords a stroker kit for the 400 you already have.

rohrt,
Thanks for the advice - my 400 is strong and doesn't need the build right now. I'm saving the money to spend up at the Pontiac Nationals next weekend. Thought it sounded too good to be true - now if it was judge 428..................

OK, I give. What's a "GTO Judge 428?"

I thought the only 428's dropped into GTO's were done by Royal Pontiac as "Bobcat" treatments?

I.e, dealer swap a la Yenko Camaros, etc.

Royal Bobcat Article

If that claim is true then that was one really rare car and you should go back and get the entire vehicle.

Saw the same article. I doubt this one was "born" in a Judge. The car was wrecked (per the seller), no longer around. Sounds kinda fishy.......

Stick with your 400. I had to have a 428 for my 67 bird. After spending a larger than normal amount for internals it runs awesome but my pocket felt a little raped....

I agree.

What makes the 428 such a desirable engine?

According to my engine builder 428's are very close to what they call a square engine. Bore and stroke are very close to the same.

I think I ended up with about 4k in my rebuild. On the high side but not crazy. Pistons were the only hard parts to find.

That 428 looks pretty cool on the hood and truck!

28 more cu in.....lol

There's no replacement for displacement...LOL

after parts and machine work almost $6,000.00 now that did include Doug's ceramic coated headers. correct 428/400 ho quadrajet, roller rockers, crower cam/ lifters, you know go fast stuff.... But I will have to say this is by far the FASTEST car I have ever owned....

Wikipedia indicates that the difference between the 400 and 428 (besides bore/stroke) is that the 428 has larger journals.

That being said, Pontiac's are slow RPM engines, the 421, 428, 455 cranks will rev slower than the 400 & smaller engine. Interstingly, the 400 & smaller engines use the same stroke, 3.75".

Steve

Think my 428 didn't get that memo. lol

Mine revs pretty well also. I didn't take into account all the add ons and the cost of the engine. Probably close to Jose's all told.

Mine is also by far the fastest car I have ever owned. Would stomp the 454 73 corvette I onced owned. I happy with this engine. It sounds awesome. Nice and lumpy with the Isky Mega 280 cam.

Plus I love lip reading the guy in the car next to me at a light as he smacks the passenger and mouths out four twenty eight.

The 428 is just a factory stroked 400. Even had the same bore dia so only the pin height is different. The factory used dished pistons so factory 400 heads were used on all 428's and got the same compression ratio. Not sure what 'extra' stuff there is to it in addition to a routine rebuild over a 400. I have not piston shopped in a while but I would be surprised if they cost much more than any quality dished piston. Or, get another set of heads that will get the compression ratio where you want with flat tops. Cast iron heads are cheap and plentiful. 428's use the larger crank journals shared with the 421 and 455 but there is no significant extra cost there. Anything else you decide to do extra is just that, extra. They came with and accept all the same V8 (326-455) stuff. I love my 428, had it since high school.

I'm going to look at it tomorrow morning. The guy claims to have known the original owner of the judge. He supposedly ordered the car built. The guy says he has pics of the car when it was new. He gave me all the numbers off the block and heads. The only thing he couldn't find was the head ID - said there's no large numbers on the middle two head ports. Approx 63k on the car when wrecked. heads are off, so inspection should be rather easy. I'll bring the calipers and measure the valves. Hopefully they'll be 2.11/1.77's. I figure for what he's asking a good quality 428 would be well worth it.

WOW! 1969 YK block with 4 bolt main, 390 HP from the factory with 16 heads that had the 2.11/1.77 valves......................at least that's what I'd hoped to find.



2 1/2 hour drive. YE block 2 bolt mains and 1969 47 heads, which according to 3 different websites came on a 350 engine rated at 290 HP.

5 friggin hours of driving for that. He wanted 600. The block and heads were clean, not what I was looking for.

The hunt goes on...................

They may be all gone but Ace Pontiac did have small journal 428 cranks. I would snag one before they are all gone. They may be gone now.