Been sitting on an LT1 radiator for a while, finally got
around to doing the swap.

I prepped the piece by placing little plastic "dams" at
the bottom of the two unused heater hose bungs,
and "painted" the inside of them with JB-Weld. After
that layer semi-cured I filled the rest of the port.
I also epoxied two small thermostats next to the
outlet neck, for later use in fan control rejiggering.

Radiator core is at least 50% fatter, not quite 100%.
Fit-wise it's a dead swap.

In 77F air, fans a-buzzin', coolant temp at idle & cruise
is 187F. I went back to the stock 'stat, from a HyperTech
"160" that gave 177F. A 50-100MPH WOT pull saw the
coolant temp rise to 190F (peaked about 2 sec after the
end of pull. then back down). That's plenty good for the
strip, though I was more interested in extended duty
and summer w/ air conditioning on, not pinging. I also
put a bottle of water wetter in there, and new DexCool
(the old stuff came out looking and smelling like new,
so I'm staying with it).

I also took the trans cooler off the stack and mounted
it "Dope style" (or sorta). I had planned to swap over
to a plate type that I had mounted muffin fans to, but
could find no place for it to quite fit.

Blew & picked & shop-vac'd a whole mess of debris out
of the condenser too, surprising what can get up in there
in only a year.

I got this rad off an eBay seller with a local auto-parts
storefront, for crazy cheap. I think it was under $50.
You can't beat that, if you've got time to be patient.

All told I probably spent 4 hours at it including a lot of
try-fit for the new cooler, and reinstalling the old at the
new position. Idle seems improved (probably fuel boils a
bit better) and found no ping on the shakedown run.
The thing about the HyperTech / small radiator combo
was, you'd get cool running when it doesn't count but
swing hot as soon as you hit load. LT1 rad has more
coolant reserve and way more fin area, and it's my
observation that the stock 'stat swings less in temp
than the aftermarket, from when I originally put it in.

 

Damn thats cheap for a new radiator !

 

Crazy cheap, but I eSniped it and they honored the
price.

 

so you basically went from a single core to dual core radiator correct?

 

What are the overall dimensions of your trans cooler? I eventually want to install an engine oil cooler, and will probably end up mounting it in a similar configuration.

 

So an LT1 radiator is the same as an LS1 only thicker? Interesting. Wonder if there is any advantage for autos who no longer use the stock cooler to get an M6 radiator???

 

The core is thicker, the tanks the same except for the
fittings.

Ditching the trans cooler in the automatic version, will
only get you a bit more tank volume. Me, I route from
trans to cooler to rad and back to trans.

Cooler is the Hayden "24000 GVW" I got at pep Boys
years ago. About 8x12, I think.

 

Im running the big B+M at 11x11x1.5 plate style. It cools so good its spooky However, I noticed good temp drops by bypassing the factory radiator heater, which is what I think it does. IMO the stock radiator has 2 fluids running in it and obviously they try to equalize to a degree. If coolant is 200, well its actually warming my trans up. I do however do a lot of driving with my trans pan temps less then 130. Dont know if the fluid is designed to function properly at this temp. Likely not optimum I'm sure.