radiator question

[70 RAG TOP]

I need a new radiator for my 70 challenger.  383 magnum w/ auto trans and w/o air cond.  There are 2 sizes of rads that are available for this car(22" and 26" wide).  I have a 26" rad in it now(originally had small rad from factory because it was 318).
The actual opening in the radiator support is only about 22-1/2" wide from factory.  There is about 3" of radiator that is obscured by the radiator support and doesn't get a direct flow of air. 

Do the big  block cars come out of the factory with a larger opening in the rad support?  or are they all the same?  Would the smaller radiator(18"x22") be sufficient or would I need the larger capacity radiator?

Also any recommendations on a good replacement radiator(moderately priced) ?

Thanks Mike

[burdar]

The rad support has a bigger opening on the cars that came with a 26" unit. 

[70 RAG TOP]

Is the smaller rad sufficient to cool a big block?

Would a 26" rad be better(even though part of it is blocked by the rad support)?

I bought my 26" rad used years ago and had it boiled out.  It has developed a few small spots that are"seeping" and I'm not too confident that boiling it out really did much good.  I would rather buy a new rad and feel comfortable knowing that my new engine is staying as cool as possible.

Mike

[burdar]

It's hard to say if your engine would stay cool with the small radiator.  I assume all big block cars got the 26" rad right?  The factory did that for a reason.  I know my small block car got warm in traffic with the small rad but it doesn't have the axle package so there is no shroud.  A shroud will make a big difference.

Did your engine overheat with its current rad?

[BIGSHCLUNK]

NIKKI was originally a 383R/T   22inch rad... still run that rad w the HEMI but have added a pusher just in case...

also recommed a fan shroud!!

[Alaskan_TA]

Even 440-6 cars came with the 22" radiator if the gears were 3.23s.

Things like AC & gear ratio affected the original radiator sizes.

[Aussie Challenger]

Seems to be one of the great mysteries of MOPAR's, big blocks got narrow radiators and 318 cars got 26", not all the time though. Yes the 383 should work well with a 22", fit a cowl and viscous fan.   

[70 RAG TOP]

Yes, it was a constant battle.  My car would often overheat and would run like crap.  I think it was a combo of factors ie tired and dirty engine, rad clogged w gunk etc.  It only has a 7-1/4 rear w/ 2.76 gears.  I will eventually upgrade to an 8-3/4 once the 7-1/4 gives out. 

What's the best?  aluminum or brass.  Does the alum. dissipate heat and cool down much quicker than the brass?

Any suggestions/experience with a  good brand of replacement rad and at a decent price.

Thanks
Mike

[Aussie Challenger]

Aluminum does dissipate heat better but carries other problem, mounting is one and electrolosis another. For a stout street cruiser I would stick with the brass radiator.   

[Cuda_Kevin]

Aluminum does dissipate heat better but carries other problem, mounting is one and electrolosis another. For a stout street cruiser I would stick with the brass radiator.   

What the heck is electrolosis?  I talked to a radiator guy and he mentioned that about aluminum rad's.  What is it and why is it bad?

[Alaskan_TA]

From www.dictionary.com

Science Dictionary
electrolysis (ĭ-lěk-trŏl'ĭ-sĭs)   Pronunciation Key
A process in which a chemical change, especially decomposition, is brought about by passing an electric current through a solution of electrolytes so that the electrolyte's ions move toward the negative and positive electrodes and react with them. If negative ions move toward the anode, they lose electrons and become neutral, resulting in an oxidation reaction. This also happens if atoms of the anode lose electrons and go into the electrolyte solution as positive ions. If positive ions move toward the cathode and gain electrons, becoming neutral, a reduction reaction takes place. Electrolysis is used for many purposes, including the extraction of metals from ores, the cleaning of archaeological artifacts, and the coating of materials with thin layers of metal (electroplating).
 

[Aussie Challenger]

In short the core can develop pin holes if not mounted properly and precautions taken.