Tiha

Have a stock 71 350 and want to swap to iron headet (NonAC) 455 9,5:1.

Not sure but in stock form it must be a 3 Row correct???

Any Summer- EXPERIENCE with the stock 3 Row radiator / 455 and no shroud but with FlexBlade ...?

Tiha

Another quest: will a big flexblade fit in a stock 71 fan shroud like this :

https://www.rockauto.com/en/catalog/...n+shroud,10707

oldcutlass

Why not get a stock clutch fan assy? They move a lot of air. On your 3 core question, I always advise to try it first and see if it will work.

2blu442

3 or 4 row, depends on the climate where you live. I agree with oldcutlass, rather than a flex fan I'd go with the factory clutch fan. John

Fun71

I agree with the others. Flex fans do not move as much air as the factory clutch fan. The flex fans were designed to have lower parasitic power loss, NOT to move more air.

ronskal

The 3 row should do fine if it is flowing properly and if the 350 radiator is the same dimensions as the 455. My 455 with A/C has a 3 row from the factory but I have no tested it to the max yet.

Kennybill

Jmo, 3 core, shroud, and a good clutch fan and 180° thermostat. Flex fans have been around for years and I've tried one not so much for cooling but supposedly they freed up HP. Wrong, I've seen test on them and they don't work. I stick to factory clutch fans. As I said, jmo.

My442

Be sure all of the rubber flaps are installed as well.

These flaps keep the incoming air flowing thru the radiator.

RetroRanger

I have the 3 row 350 rad in my 455 car. it wont keep up on the highway temps above ~60°, round town and speeds to 50ish no problem stays at thermo temp, at 70mph it starts heating up after 10-15 mins i get off the hiway, looking into a 4 row now

factory clutch fan w shroud and all rubber flaps in place.

oldsmobiledave

Re-core your existing tanks with a high efficiency 3 row core. I put one in my 1972 W-30 4 speed car in 1998 and have never had a moments trouble with it.

70sgeek

Auto City Classics AT6872 aluminum radiator (2-core, 1-1/8" tubes)


http://www.autocityclassic.com/cheve...inum-radiator/


keeps me at 180 all day long in FL heat!

RetroRanger

w a BBO or SBO?

olds 307 and 403

That is a nice looking rad with bigger than the usual dual 1" cores. I may try that one if my 2 core on my 350 doesn't cut it.

Tiha

How i can identify if it´s a 3 or maybe a 2 Row actually in the car?
Have try to check the rows in the tank but cant see anything than water

Tiha

..really have no idea where are these rubber flaps sits ..never heart of this..give some input

Tiha

..always thinking with AC it has heavy duty cooling = 4 Row

Tiha

IF my car has a 3 Row currently (???) and change to this 2 Row must i change the upper / lower radiator brackets ?????

Tiha

Does anyone have any part numbers for a good clutch fan

70sgeek

Here's the combo I use on my 350 - factory shroud, the Auto City 2-core aluminum rad, Imperial 220618 fan and 215045 thermostatic clutch


I'm running a '72 350 with stock-length Flo-Kooler mechanical water pump and all play very nicely together

RetroRanger

Yeah 455 is a different animal, my stock setup had no problem w the 350, same setup w 455 can't shed the heat fast enough at hi way speeds....it's fine at lower speeds

Fun71

I did similar with a high efficiency core in the original 3 row end tanks on my car and it stays cool during 115+ summer temps, on the highway, with the AC on.

android 211

Many people recommend the Hayden fan clutch. I think the regular street unit is the 2705. There are heavy duty and severe duty units but they will probably just lock all the time and you will not get the benefit of freewheeling when engine isn't hot. The severe duty is for trucks and require a fan with more pitched blades. I just switched to a 7 blade clutch fan from a 6 blade flex fan and saw lower temps on my BB 87 Cutlass.

Tiha

thanks man