Thumper 10 Report post Posted September 20, 2010 I recently stroked the 351W to 408 and she wants to run hot in town. I have a brand new radiator (standard size), new water pump, hoses, etc and new temperature sending unit. Do I need to upgrade to a larger aluminum radiator? I thought I would ask for opinions before investing any more money. I have no temperature gage just the original unit on the dash. Thank you. Quote Share this post Link to post Share on other sites
PaleRider 12 Report post Posted September 20, 2010 Assuming you are using a shroud. Without one - will run hot. Invest in mechancal gauge so that you can get the real temp. When runninmg hot does it boil over? Quote Share this post Link to post Share on other sites
Max Power 74 Report post Posted September 20, 2010 If you have the 20" radiator, upgrade to the 24". Quote Share this post Link to post Share on other sites
6T9Mach1 12 Report post Posted September 21, 2010 You need to hook up a mechanical gauge...the original oem gauges are not very good and can be all over the board. Do this first before worrying too much. Quote Share this post Link to post Share on other sites
70Mach 10 Report post Posted September 21, 2010 Try some "Water Wetter" in with your coolant. I'm using some in my 408C and it runs about 10-15 degrees cooler. http://www.redlineoil.com/Products.aspx?pcid=10 Quote Share this post Link to post Share on other sites
EastYorkStang 63 Report post Posted September 21, 2010 Water Wetter work wonders! Used it in my '70 and it must have dropped 10-20 degrees... Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted September 22, 2010 Silly question, but you got the thermostat in correctly? My friends 408 with aluminum rad and dual SPAL Fans runs a bit warm when in traffic, and he has the Edelbrock water pump good radiator and fans and it still hovers in the 190-200 area in traffic on HOT days...the water wetter did help him out tho:) Get that mechanical Gauge in there tho to verify it. Mike Quote Share this post Link to post Share on other sites
Thumper 10 Report post Posted September 23, 2010 Thank you for the replys. There was no shroud when I bought the car a few years ago. There is a gap between the sides of the radiator and the frame that could probably be covered with a thick rubberized material to help direct more cooling air from the electric fan to the engine and not bypass the radiator. It looks like a 24" radiator is in the future and I have to look into the direct reading gage and wetter water. I would like to put a tach in also but that will have to wait for my Sugar Momma to come along. Thanks again for the advise. Quote Share this post Link to post Share on other sites
ForceFed70 14 Report post Posted September 24, 2010 Get a shroud on there before you do anything else. Quote Share this post Link to post Share on other sites
