Big block heater core question (Need help)

[RatNova71]

My original heater core sprung a few leaks tonite. My car has the small block core/ heater box now and i would like to do a factory big block type set up. Is there anything i need other than a factory big block heater core? I know i will need to drill holes in my heater box in the correct location, but is there any other parts i need to buy other than the core?

Thanks for any help you can give me

[71SS]

That should be all you need. Do you know they repop the BB heater core covers also.

[RatNova71]

Ya I know, I'm CHEAP!!! lol

[Toms73NovaSS]

Becides drilling the holes I needed to modify the passenger side clip that holds the heater core into the heater box.

Other than making a outer coverplate to dressup the holes with a gasket it is an easy job. The cover plate and gasket also stabilize the tubes so that they dont rub against the inner holes.

here is a pic of my home made cover plate:

[RatNova71]

Thanks alot Tom. Just what i needed

There was a question on another thread about a bb heater core and core support.
Does anyone know if a sb core support on a 68-70 Nova will work for a bb transplant? I know the shroud is different.
If there is a difference, how difficult is it to change out core support?

[RatNova71]

Originally Posted by americangraffiti

There was a question on another thread about a bb heater core and core support.
Does anyone know if a sb core support on a 68-70 Nova will work for a bb transplant? I know the shroud is different.
If there is a difference, how difficult is it to change out core support?

Are you talking about the heater box, or the radiator support ?

Rat......radiator support.
I didn't think you had to change radiator support when going from small block to big block.....just the shroud
AG

[RatNova71]

Hi american, let's just say you have very good taste in cars and color combos...

Yes, the radiator support has a bigger opening cut out of it on the factory big block cars, due to the radiator being a few inches wider. Other than that, I don't think there is any difference. (Maybe a Guru could confirm this ). However, if you are not trying to make a 100% correct clone the small block stuff can be made to work. With a smaller aftermarket fan for instance. I still have the six banger shroud on mine which is really just a cover, not a true shroud.

I have a small block 3 row radiator on mine too. Cools OK, but would be better with a shroud. I'll get around to putting one in, one of these days.

btw, I hope your not thinking of switching out your small block, that thing is perfect just like it is! Is your car a factory SS? 70 or 71? and, what color is that? Thanks

Hey Rat...
Yeah, I found a vintage 427 last summer and am in the process of having it built.....also I am installing one of the Keisler Tremec 5 speeds behind it.
Engine bay will be done in correct hoses, clamps etc.
The car is a 5 owner true SS that was purchased new just 20 minutes from where I live. I even have talked with original owner. I've got the protecto plate.
Engine and tranny will be bagged and stored since they are all numbers matching.
I'm not buthering anything up for the install.....just in case I take it back original later.
I am going to be using my current three core radiator but with a big block shroud........anyway I'll post some pics when I'm done.
AG

[RatNova71]

Hey, that is really, really cool. Can't wait to see it!!!

Andy

Rat........hey, we're twins

[RatNova71]

Well, got the old leaky core out tonight (real fun job! ) Picking up my Autozone replacement tomorrow (better be for a big block!) and I'll probably pick up a new blower motor as well, seeing as its a bitch to get to.

Whole lotta trouble for a car that hardly ever sees cold weather driving, but at least it will be working correctly.

[RatNova71]

Well, guess what... Autozone replacement says big block but its for small block, as well as advance auto... so much for getting one cheap.

Ordered one from NPD for a 69 No A/C big block camaro $49.95, should be here in 2 days. Did alot of checking and they ranged from $49 all the way up to $85 from yearone.

Anyone know what would be good to use to seal the blower box back to the firewall? I used to have a roll of refrigerator caulking, but I lost or threw it out somewhere along the way. Think maybe a home improvement center might carry something like that?

[Toms73NovaSS]

What I did for the seal between the outer box and the firewall is:

First I place it in place and noted where the most gap was (in my case where the cowel sides and fire wall met) and I then put seam sealer on the outer box inside lip. Built it up a bit more in the areas where it needed it. Then let it dry. Basically creating a semi flexable gasket. I'm sure silicone would work also.

The reason that I did this is I did not want to mess up the nice paint job of the firewall and heater box by just spreading something in the gap.