Hot Rods AD_NAPCO's 39 GMC Rocket 324 Build

Okay, so this thread is THE thread for my truck engine build/resurrection/project...

Thread with some history is here: http://www.jalopyjournal.com/forum/showthread.php?t=619252

Finally got the front clip off the truck so I could get a breaker bar on the crank bolt. Low and behold, she moves real easy, which is encouraging. I had dumped a little marvel oil down each plug hole about two weeks ago and just let it sit.

Pulled the valve covers just now and while everything looks pretty clean, there is one issue with a badly cracked stand-off? Cap? for the valvetrain. I've never seen anything like this. Anyone have a clue what might cause something like this? Almost looks like it was hit with a punch and a hammer or something from the circular mark in the middle...

 

Maybe it got cocked while being being torqued down? Where's the always in the way when doing a V-8 swap steering box? Under the manifold?

 

Maybe...

The steering box/column is another mystery. I have no idea what it came from. Some kind of early Hydra-Matic. It's tucked under pretty decent but not much room.

 

That's an alignment dowel for the oil feed holes in the rocker shaft. Looks like somebody whacked it one too many times.

 

Looks like I get to see if anyone's parting out a 324.

 

I can check in the AM to see if I have a spare. PM me Friday in case I forget

I did get to talk with a really old timer on Olds rocker ratios and differences in the two types of stands for the 2 ratios... Just in case anyone is swapping them.

This old racer said that when they swapped different ratio stands on their existing shafts, that there was a size difference on those aligning pins. I think he said one was stepped or tapered, something like that. I don't recall his instructions on which part should be modded; either the pin end or the hole in the shaft, but I think it would be obvious to what should be easier. Just a heads up for anyone swapping things around between 303 and 324.

He also said many rodded Olds motors got stands swapped, even some later motors getting the older stands for a special ground cam, so you should always check a old hotrod motor to see which type you have before ordering parts like that single stand.

The easiest/best way to ID a 1.8 ratio stand from an original 52-58 is to pull the big bolt out. Then look down it's bore in the stand. If that bore for the bolt actually bore though the edge of the bore for the rocker shaft, then it is a 1.8 stand.

A 1.5 stand from 49 to 51, when looking down the head bolt bore, will show that it's bore is no where near enough to intersect the rocker shaft bore.

 

Looks like somebody may have forced a pin too large in.
No drilling the shaft it's harder than....

 

i had the same thing happen to one of my stands (1955 324ci) no one sold them at the time. but yorgatron was kind enough to hook me up with one of his spares. i think fusick sells them now though if you cant find one getting parted out

 

GOATROPER02 can probably set you up

 

This s great info... I'm glad I posted this!

I think it's a 1.8 stand because, while it doesn't quite translate in this picture, if I eyeball line up a straight edge to the rocker shaft, looks like it just sneakes over the edge of the bolt's bore. Make sense?

 

Yes, bores look like they are close. A 1.5 would have the rocker shaft just about halfway between the large and small bolts.

The reason the 1.8's are so close, is that when GM changed the ratio, they just moved the entire shaft over to compensate for the length of the new rockers, and did that to get the pushrods to line up with the holes in the heads.

I will look to see if I have the proper stand with the pin hole. I know I have a spare 1.8 partial rocker shaft with "some" stands still on it. I just don't know if the one with the pin hole is still on it.

 

Are you going to keep the Olds motor in it,I am thinking about installing a Olds and hydro in my 37 Chevy p/u if I decide to get rid of the 235.

 

I just went to see an older guy who had a 37 Chev coupe for 30+ years, survived cancer and finally decided to run a 303 w/37 LaSalle in it. Might be the same as a truck for fit; this thing really looked impressive in there. It sat high but fit good. Stock steering box, and the starter cleared no problem. 2x2 carbs with Edelbrock covers.

He also made 4 tube tri Y headers by splitting the center port.

It all looked like a real nice fitting swap.

 

The olds looks like it fits good in the 39 and clears the stock steering which I wondered about,I got a rattle in the 235 thats internal but has been making the noise for 10 years but seriously thinking about Olds power and dressing it up as a 49 motor to look like its been in there since the 50s.

 

F&J... Let me know. PM me if I don't PM you first, and thanks!!

junkyardjeff, yes, the plan is to keep the Olds/Hydra that is in the truck. My original plan was to do a 302 GMC build but this truck was taken way too far to put the rocket in it so I'm gonna have fun with that instead. I've been around straight 6's my entire life and am looking forward to doing something different.

As far as the steering being stock in my 39, the column/box is not stock. I'm not sure what it's from but it's meant for a Hydra-Matic. I'm not sure that it'll clear the stock 37 Chevy truck box. Truckedup would be a good person to ask about that possibility, he had a 37 Chevy pickup.

 

The column has to be for a truck since it looks like it bolted in the stock location,I think the trucks got the hydro in the early 50s.

 

First year for GMC to get Hydra-Matic is 53, and Chevy trucks 54. Those steering columns are completely different than this one in my truck.

 

Ok, I do have one 1.8 stand with a good pin. Just took it off the shaft and it's good. Send me a ship add'y, and I can likely USMail it Sat.

 

PM Sent! Thanks!!!

 

Been playing with the truck over the past few days and yesterday among other things I pulled the 40 dash out and put the 39 dash in... I like the look better already.

Someone mentioned that they thought the steering column clamp/gear selection indicator might be home made... At first I disagreed, but now Im starting to think they were on to something, because this thing has no maker's marks that i can see, and it's made of to solid cast chunks of aluminum... Pretty impressive. Anyone got a H-M gear selection indicator they wanna sell? This one has about had it. (Edit: HAMB'er Tejano has ID'd the plastic shift indcator insert as being specific to 52 Olds, so I'm on the hunt for a 52 Olds 'quadrant' as he called it. Never heard that term but I don't doubt he knows what he's talkin about.)

Anyone able to ID the make and approximate vintage of this steering wheel? I cleaned about a yard of greasy mud off the grip and it seems pretty well crack free. I wish the chrome was in as good a shape. It was pretty pitted but most of the big hunks knocked off pretty easy. Those are all the parts that were there.. I assume I'm missing some contacts and a spring at least, and some kind of filler to close the giant gap between the column bell and the wheel base... Ideas?

Also some better shots of the steering column/shifter... Any ideas what it might be?

 

Some guys in another thread ID'd the column as 40-48 Ford... Man this truck is full of surprises.

I got a couple questions about the layout of the 324...

The truck had an unidentifiable Carter AFB on it when I got it, and without digging into the carb and getting individual part numbers to Carbking, there was no way to figure out the application to get a kit with. He advised I find an OE 4GC. Found one. Got here today.

Now I know why it had an AFB on it, as well as why the generator is mounted to the top of the intake and not on the passenger side exhaust manifold. In the stock location, the generator is really crowded against the inner fender, and so they moved it to the intake. Only problem there is that there's no room for a 4GC with the generator up top. In comes the AFB which is wider and shorter front to back and leaves room for the generator to clear. Well... I'm going to try and make the generator work in the stock position... If I put the generator up top, I lose the ability to run any kind of multi carb setup if I wanted to go that route. Right now I'd just be happy with the one four barrel.

So, with that, I have questions.

1) Should there be a spacer/insulator between the carb and the manifold, or just the one gasket? I ask because the linkages just barely squeak by the manifold during operation on this 4GC and I'm wondering if they should have a bit more breathing room or if it's meant to be that way. If so, anyone got a recommendation on where to get one?

2) I'm gonna need a generator adjusting bracket, and maybe a mount bracket too. I have no idea if the one they used up top is the same as what should be on the side. It bolted up... Pics will show where I'm at. If anyone has good pictures of a 324 that is laid out really cleanly, as far as plumbing and wiring and all that, I'd love to see them. PM me or email me if you have pictures.

3) Any recommendations on the best quality reprint, or original version of the factory shop manual, and as far as aftermarket manuals go, do you guys like Motor's or Chilton's better? I have a couple Motor's truck manuals and they are pretty handy.

 

I thought that column looked more like a Ford product but the steering box looks original.

 

Maybe the box is stock... I don't know. I have yet to get it out of the the truck to fully investigate it... There's a lot of unanswered questions. The pitman arm and draglink are pretty twisted up so that makes me question the box and the location because the steering geometry isn't quite right. That may also be because the spindles may not be right being that the truck has 5 lugs on the front...

I have to pull the starter back out to pull the steering box. I might do that tomorrow.

 

Motors manuals are ok, and Chiltons is good for wiping your ass with but if you want useful information buy a shop manual.

 

The reason I asked about all three is because for example, Chevy truck shop manuals from the 40's-50's are alright, but GMC shop manuals of the same year are MUCH more comprehensive, and the Motor's manuals fill in some blanks. So, my plan was to buy a Olds shop manual, and then supplement it with either a Motor's or Chilton's. I guess Motor's it is!

 

I don't remember any carburetor spacers under any of my Olds'

it looks like the generator bracket you have there is the one for bolting to the manifold, top mount brackets are stamped, and side mount brackets are cast.
also looks like the front bracket hole has been modified, do the pullies line up?
the hole for the lower end of the side mount placement does not look like it has been drilled and tapped, unless it's too full of gunk to see the hole, it's the ear on the water pump..
also the top bolt hole on the generator is clocked wrong for the stock side mount arm, it looks like it is right for the top mount.
the arm in the lead photos is wrong, the generator should roll over to just clear the valve cover.

there may be some information in the Motors manuals that isn't in the shop manuals so I guess it wouldn't hurt to have both.
original, reprint or cd versions of the shop manuals can be easily found on line and are an excellent investment.

 

Re: mounting location of generator: You have three tapped holes on the drivers side of the intake, two are on the water crossover. Make a bracket out of some plate and bolt it at those three points. Mount the generator to that and it will set just above the valve cover out of the way for any multi carb set up. You can order a chrome adjusting bracket from Summit or Jegs and just cut to legnth if need be. This is how I did it in my 41' Ford conv. If I can figure out how to post some pic's I will.

 

Thanks Paul... This is good information. I'll do some cleaning and mocking up and I'll notate my next round of pics in photoshop so it's obvious what's what.

550Coupe, I would love to see some pics. Adding pictures is pretty easy, and the forum will resize them for you.

You'll notice two ways to reply. One will say "Quick Reply" on a small button lower right of the text field, and a larger button lower left of the ext window will say "Post Reply". Post Reply is the one you want. When that comes up, there'll be two windows. The lower window has a red cross bar that says "Additional Options" Second field down says "Attach Files" in blue, and a button under is the one you want to click that says "Manage Attachments." From there a floating window will pop up, and you just browse to each individual picture you want to upload. Pic the pictures one, for each field, and then hit the upload button. Once they are uploaded, you'll see the fields go blank in the floating window, and then you can hit submit reply and they will show up.

Hope that made sense.

Thanks for the help!

 

I have had the back draft carbs fron the early 303 and also 2 barrels from 55, and they had either what is a super thick gasket or a spacer. They have dowel pins in the base of the carbs to keep it from getting crushed. About 3/16 or 1/4 thick, I think.

I can look at a 303 53 4 barrel setup here to see if that one has the same thick gasket.

AD-Napco, I mailed the rocker stand today, you should get it mid week or so.

 

Here's the pic of my gen. bracket.