[Mr big block!]

Iv got a big block 454 4 bolt that i built and it constantly over heats if i drive it over 45 mph. if it is pulling, and tacking over 2,500 rpm it over heats. iv got an electric meizure water pump on it with duel electric fans, and a 4 core aluminum griffin radiator. Iv tried the timing, the gas air adjustments on the carb thinking possibly to lean.. But nothing works. and the entire engine is brand new. edelbrock heads, intake, complete rotating assembly etc! Iv checked the thermostat, and gone over everything a hundred times, just cant figure it out.
Can anyone help me with this please?? Any advise i might have over looked.
Thanks guys:

[68NovaSS]

I'm not a fan of electric water pumps on the street, but can't say either way about it's efficiency or capacity. You fans should be set up as pullers, and your thermostat probably in the 185-190 range. A lot of people make the mistake of running a cooler TS thinking it will keep the motor cooler, when in fact it doesn't allow the coolant to remain in the radiator long enough for it to do it's job dissipating heat. Keep in mind a new motor will run warm for a while.

What are your temps?

[S10 Racer]

I'm not a fan of electric water pumps either. They do a poor job of supplying enough force to keep the coolant circulated. Secondly they only circulate the coolant at one speed regardless of how many RPM's the motor is turning. They are ok on a race motor where the motor is run for a quick 1/4 mile pass.

[lmsport]

I prefer a mechanical fan on a street driven big block.

Has anyone used a late model electric fan clutch on their hot rod?

[68NovaSS]

I'm running a pretty radical tunnel ram BB in my T-bucket, relatively small 3 core "T" radiator and one 14 inch puller electric fan, it never gets over 200* in traffic on a 95 degree day.

[65 Imp SS]

Originally Posted by Mr big block!

and a 4 core aluminum griffin radiator.

Which griffin rad do you have? I see listings for:
Pro series 2 row 1" tubes cooling for up to 400hp
HP series 2 row 1.25" tubes cooling up to 600hp
HP Max series 2 row 1.5" tubes cooling for beyond 600hp
http://www.griffinrad.com/PDFs/ProdCatGreen.pdf

[prostreet6t9]

I run a electric pump on the street.. BBC with 14/1 comp. Electric dual fans with a shroud. even on hot days it only runs 195.I've had pretty good luck with my set up.

[Mr big block!]

My Griffin radiator is a 2 row 1" tubes. I have the 35 gallon per hour electric pump. A 165 degree thermostat. That may be one of my problems, the thermostat is too cool. My bad i wasn't thinking about that when i put it in. I had a brain fart, lol. I would like too change the water pump to a mechanical, but that would mean i need to replace all my billet aluminum brackets as well. Another huge cost, but not as huge as a motor rebuild. I have nearly $15,000 in this motor so i need too be more careful with simple little mistakes as a thermostat. I have 2 fans on it as well, 1 pusher, and 1 puller, one at each end, in the front, and back of the radiator. Guess I need too make a couple changes. Thanks guys for your help. Love this site. So many helpful people.