540 big block Shafiroff or Bill Mitchell??
 

Which way would you go? The Shafiroff Ultra street with the Merlin III block is a bit more money, but it makes more HP. You can get an all aluminum version from Bill Mitchell for 12,995. Are there any disadvantages to running an aluminum block on the street? If you went with the Ultra street are the callies crank and rods upgrades something I should get? This is going in a street car that will see limited dragstrip use and maybe some scca parking lot stuff. Any and all opinions appreciated. If you have had experience with a different builder in this price range please advise as well. Thanks, Paul

i would go sharfiroff,he's one of the best engine builder's around.

i have been running an aluminum block on the street for years,first with a 540 then a 632 and now a 710,plus they were have filled.they need a very good radiator.my 710 runs 195-200*,with a water restictor.i waiting for some hot weather to really test it,the motors brand new,and thats with the air on.

i would get the callies crank,billet rods or h-beams.

the aluminum block will take 115 off the weight of the motor.

also reher-morrison does some really cool street motors.

I'll 2nd RM, they build some wicked stuff.

Aluminum block will work great on the street and actually runs a good bit cooler than iron, plus it's 100lbs (give or take) lighter.

Does anyone else see the humor in auto-xing a 540" big block car? I LIKE IT :cool:

What kind of HP are you shooting for?

i will tell you a 540 should easliy make 800+.my 710 makes 1100 on pg,i build my own.

I'm thinking
 

650 reliable HP that can be made on 91 octane at 4500 ft elevation.

I have zero experience with auto cross, grew up at the dragstrip. But, there's a casino about 3 miles from the house that has scca autocross once a month during the summer. They use a christmas tree start and a straight away before the twisties start. The way I see it, I can get there quick and waste a set of tires around the rest of the course and have fun scaring the cone watchers, lol.

Thanks for the input.

i have had both a shafiroff 540 that made 1055.hp great peice ,great service , race motor . and a mitchell 540 that made 704 hp street motor . never had to turn a wrench on it , or tune it .

both were good parts ..

for the money a 632 isn't much more,and the tq and hp made will be sweet

How much can you build a 632 for?

20-25g depending heads

man i didn't realize shafiroff was cheap for a 540,damn 9g

632 out of my budget
 

I have decided on the shafiroff 540 with the Merlin block, callies crank and rods, 850 cfm carb set up, msd ignition, sfi balancer. All said and done just under 12,000. I couldn't justify the aluminum block as much as I want it. I can't rationalize the extra cost to save 125 lbs.