New project, new motor, more questions to come.

But for the moment, Can you manage an occasional 600-HP with a 22-inch radiator ?
This is an E-body pump gas deal. Manual tranny, no A/C.

It would be a PITA to have to convert to a 26" opening. But I would do that if absolutely necessary.

Radiator size based on hpnever made that much sense to me, for the reason you point out.....how long are you running at WOT ?

I run a 22 in a 70 Cuda, 440, 4 speed, no AC. Gets to 210 on a warm-hot day in traffic. If I ever had a problem iam sure a new 22” rad would solve it.

As long as your system is working properly you will be fine.

It will be marginal but might work if you have a shroud and a big fan. The radiator needs to be in excellent shape.

I had a 22" side tank alloy radiator for my 496 RB, auto, 4800 stall around 600hp and only got to 195 once on a very hot day. Plastic shroud with a light steel flex fan. I am using the same radiator for a new 596" predator motor in my Cuda street car so i hope it will be ok for that too.

Is it a two core, three core or four core radiator?" Is it stock or a replacement Hi Po desert cooler type radiator?
Lots of ways to look stock and still cool way more power than stock

I have two b-body cars and both have 440's with 22" radiators. one is stock, all iron engine, stock exhaust, ramcharger fresh air stuff, etc. this one won't run cool in the summer with a 3 row brass radiator; about 325hp. the second one has alum top end, headers, cam, etc and won't run hot if you drove it thru hell. the second has a 4 row brass radiator; about 450hp. I don't think horsepower ratings on radiators means much. how much time are you going to spend at 600hp vs 50hp? a lot of factors other than horsepower.

Call GRIFFIN or BeCool and ask what style will work best in your situation.
Does an E body have more room between the motor and radiater than a early a body? If so you may be able to use a short fan clutch and stock AC fan which beats electric fans hands down IMHO. If you have room then a four core aluminum with clutchfan and fan shroud would be your best option to stay with a 22 inch opening. Also make sure you use what ever seals the factory used to keep air from coming back around into the radiater a second time.

Yes you can. My Dart is a street/strip deal, pump 93 n/a small block that has ran 6.40 @ 109 at 3350#. Even going back to back to back passes at some street car shoot out races I've never seen over 185° (160° stat) with the current 434 or the previous 408.

I'm running a generic 22" two core aluminum radiator from a local roundy round shop, Flow Kooler water pump, MP Viscous fan kit and a factory shroud for a 26' radiator that I cut down to fit.

I called US Radiator, told them what I am running and they have since built 2 custom radiators tailored to my set-ups.They know their stuff and I had very good customer service from them. Neither car has gotten any hotter than normal, ie 180*. I do run shrouds and thermal clutch fans properly spaced from the radiator. I tried running the SPAL twin fan set-up with controller on my e-body and it worked too. I ended up going back to the factory style mechanical fan just because.

OK, Thanks a lot gents !
Don't have a radiator yet but it will be a good one, an appropriate one.
Onward and upward.

I have one for sale on this forum, new in box
Post dated May 8
Joe

I went through the same scenario when going from the 440 to 520.

The temp would creep up on really hot days. (FL 95 plus) with the stock brass 383 radiator.

Went to an aluminum 2 row with 1" tubes that was supposed to cool it, well, it did not. It acted exactly the same.

I then went to a 4 row, no other changes, and it would stay at about 165 with a 160 stat. I then took off the clutch fan and put 2-10" pullers on it thinking the temp could be regulated with the stats on a thermostat, no Bueno, still too cool.

Currently I have one fan set at 190 with a 180 stat, the only time it kicks on is when I hit a long stop light, but, it goes right back off once the car starts rolling and gets some air across the radiator face. I have the other fan on switch for cooling between rounds.

Bottom line is, go for a 4 core, you should be just fine.

I just went thru this with a numbers matching 1970 Roadrunner that I put a 511ci engine in with 10.5 comp. I wasn't about to cut or change the core support. So I went with a griffin exact fit 2 core that was 26" wide. I made some aluminum brackets that bolted to the original radiator holes and spread out to mount the 26" radiator to. My thought was, I'm gaining additional water capacity and additional cooling contact surface to dissipate heat. I also had to use the Hayden short muscle car HD clutch fan clutch and a original Mopar fan. There's no sign of heating issues in the hottest of summer days in California (95 to 100 and it runs 180-185. I cant say it's ever gotten hotter than that.

I use a Mancini 22 inch talor made alu radiator in my Challenger whit a 505 stroker around 600 hp and a mr gasket 160 f thermostat highflow mp thermofan cloutch 5 blade pkg and never have over 185 f on hot summer days on idel for long times

Just curious, why would you have to "convert"? Even if the opening doesn't take advantage of the full 26" rad, it probably still can benefit from going to the 26. My Cuda has the larger unit and it's a direct bolt in despite not really paying attention to the opening.