Does anyone know anything about a 428 service block. I've located such an animal and I've been told they are actually a better block than the 428CJ and have a CJ crank in them. For some reason they seem to be cheaper than the CJ block. I'd be interested if they have as much potential as I've been told. I'd like to find out the good, the bad, and ugly associated with these things.

Thanks,

Tracy

 

They are pretty much the same as the production car blocks. Just an over the counter item. It's the same casting as the CJ. These were sold as replacement blocks for the 428 CJ/SCJ. They were still cast at DIF and were available till 73. The main reason they are cheaper is they are a replacement block. Guys looking for R code original blocks are shopping for date codes in most cases. Plus a original CJ block is more "correct" in restoration circles. The service block has the same thickness cyl wall cores, crank webbing and beefy crank saddle area as the CJ's. Originally the 428 service blocks carried a C6AZ-6010-F part number. The 428 service blocks have the vertical ribs and have no casting numbers. Date code is present and will have two dots under the first number. This will determine it's a 70's casting. I'd also check the cyl wall core thickness with a 13/64" drill bit shank. If it's a snug fit...shes a 428. You gap the wall cores through the freeze plug holes in the block.....

G.

 

thats a cool little trick!! thanks for the tip..

 

G, is right on the service blocks, I have a 69 CJ block, and a passenger car block, and of course there's a difference in the crank web saddle's,and its rumored that the CJ blocks were the only one's with a higher nickel content in them? I havent seen any proof of this..and the block if it is proven to be a 428? It will work good for your application!! You can look in my gallery for bare block CJ Pics...good pic in there of the crank saddle's..

Edit: Correction! I know I have one 69CJ block and after looking this morning the one I thought was a passenger block is indeed a 428 service block!!

Because I cant see any difference in the web saddle's....So the only difference now is one is at Standard bore 4.130 CJ Block..and the service block is out fresh to a 4.190" bore...

I thought thats what we came up with G... LOL..Shoot..I should pay more attention to my parts! LOL..

Russ

 

Dint the 390 have a service block as well? I guess, what I'm trying to say is that I have a "supposed" 390 service block in the barn. It has the vertical ribs cast in the block and shows no sign of a casting #. Could it be possible I have a 428?

Hell, anything's possible............ but my luck is that it's a 390. Guess the only way to check would be to pull a head and mesure bore.

Mike

 

I run a 428 service block in my race car. Cross bolt's installed. They used to be cheap a few years ago...not now!

 

so what is a 428 service block worth these days?

 

It all depends on the condition....Dont by any of these so called 428 blocks that you see on ebay...thats been a truck block D2 or D4 takin out to 4.130"..even tho they might work..you wont have a rebuild left in it!!

If its a true 428, depending on condition, maybe need a sleeve or 2? about $500 up to about a grand I think is what a good standard bore is going for now days" Its been a bit back when I bought mine..

Russ

 

How good of an engine would it be with 390 heads on it. I've got a set of D2 heads that have been ported and polished. I assume it won't be nearly as good as it could be but would it be decent?

 

It would be just fine with D2's on a 428... I was going to use my 390 C4AE-G's that I had ported and they would flow better than the ported C8 428 heads ported..and a good port job on the D2's will out flow the C8's also...

So basically what I'am saying is you'll be able to make more HP and TQ with the Big port 390 heads than you can the 428 C8's....

Russ

 

[QUOTE=mswift]Dint the 390 have a service block as well? I guess, what I'm trying to say is that I have a "supposed" 390 service block in the barn. It has the vertical ribs cast in the block and shows no sign of a casting #. Could it be possible I have a 428?

Yep there were 390 service blocks also. If your block has a std bore of 4.13 or larger then yes it could be a 428. You would really need to gap the wallcores and see. But the bore the block is at now should be a pretty good clue.

428 service blocks are selling anywhere from $500-900 depending on the overbore and condition. I've been seeing a few choice CJ blocks going for $1000-1200. These are top prices though. I sold a NOS 428 service block 2 years ago for $1300. Still in the Ford box. Not even a year later a NOS 428 service block was selling for $2250. New 428 blocks are getting hard to find.....

G.

PS.... Russ got the deal of the century on his 428's!!!

 

Ok...I know where I can get a 428 service block engine complete for $750. It has a 1UB crank and he says 390 truck heads on it. I'm about ready to jump. Sound ok?

 

Shoot, if it has good bores in it..JUMP on it!! The crank alone is worth $400 to $500 bucks depending on grind...10/10 20/20 etc..

Russ

 

G, did I get a good deal on my blocks?? I cant remember!! LOL...Shhhhhhh...If anyone of these guys ever found out? they'd never talk too me! LOL...

But I paid thru the freakin nose for eveything else!! LOL..

Russ

 

hmmmmm...so what kind of deal did you get????? I know what you mean about the rest of it though....it's about the same as paying taxes...it never stops...LOL.

I'm going to get the 428 and take my time building it up....maybe I'll go for the AOD adapter and build one of those to go behind it...then swap the whole thing out when I'm done.