dart big m block

steve4speednova · 08-01-2012, 11:44 AM

anything i need to know about useing a dart big m block for stock eliminator 396/375. i know the lifter bores are .300 tall. do they need to be mark iv.style ? thanks steve

Alan Roehrich · 08-01-2012, 01:59 PM

First off, make sure you get a 396 block, it carries a special part number, and is a special order piece.

If you're running in Stock Eliminator, you'll be using some form of flat tappet "mechanical" lifter. The 0.300" taller boss does not matter. None of my suppliers makes a 0.300" taller lifter that I am aware of, nor have I seen the need. There should be no problem with pushrod clearance, but check it anyway.

It will require full preparation, just like a GM block. You should have the dimensions checked, though it will likely not require blueprinting of the lifter bore or cylinder bore location. It probably will require the main bores to be lightly honed for size, and it will almost certainly require decking (make sure it is square, it probably will be, and that whoever does it keeps it that way).

The shop that preps it better know exactly what they are doing with a Dart block, from experience, or the rings will never seat, you'll have blow by and oil consumption problems. I see that happen a lot.

Arnold Greene · 08-01-2012, 02:05 PM

You will most likely need to change the front springs. The Dart 396 block weighs 290 pounds! Ask me how I know.

steve4speednova · 08-01-2012, 03:11 PM

thanks guys for the reply. I,m useing 1965 #962 block now, with 4.150 bore. it makes about 560 hp.to the rear wheels. what would the dart block be worth in power ?

richie 2 · 08-01-2012, 03:34 PM

are they gaining any poularity for SS applications?

Alan Roehrich · 08-01-2012, 04:34 PM

Quote:

Originally Posted by steve4speednova

thanks guys for the reply. I,m useing 1965 #962 block now, with 4.150 bore. it makes about 560 hp.to the rear wheels. what would the dart block be worth in power ?

Could be worth a little. Depends on how well your current block is blueprinted, how sound it is, and how well the Dart block gets finished. If you're putting all new parts in it, and you have the right sources, you might pick up power there, depending on how old your current stuff is.

Pedigo Perf · 08-02-2012, 07:28 AM

Quote:

Originally Posted by steve4speednova

thanks guys for the reply. I,m useing 1965 #962 block now, with 4.150 bore. it makes about 560 hp.to the rear wheels. what would the dart block be worth in power ?

560 at the tires? Why would you change anything on that 396, thats amazing!

carl hinkson · 08-02-2012, 10:44 AM

I CNC machine alot of Dart big -M blocks and this is what useally needs to be addressed.

Some block notes:
I deck all of them to a finished number depending on gasket & desired piston height
Block needs to be honed with a plate or bored & honed depending on bore
Bottoms of bores need to be chamfered
Most need the lifter bores honed, at the least checked
Most need line honing
All pipe threads need to be retapped
Oil return from fuel pump cavity needs to be done
Core plug holes need deburing
CHECK THAT THE DISTRIBUTOR GEAR DOES NOT CONTACT THE BLOCK BY THE CAM.

08-01-2012, 11:44 AM	#1
steve4speednova Junior Member Join Date: Jul 2009 Posts: 57 Likes: 0 Liked 0 Times in 0 Posts	dart big m block anything i need to know about useing a dart big m block for stock eliminator 396/375. i know the lifter bores are .300 tall. do they need to be mark iv.style ? thanks steve

08-01-2012, 01:59 PM	#2
Alan Roehrich VIP Member Join Date: May 2006 Location: Murfreesboro TN Posts: 4,930 Likes: 1,003 Liked 1,079 Times in 282 Posts	Re: dart big m block First off, make sure you get a 396 block, it carries a special part number, and is a special order piece. If you're running in Stock Eliminator, you'll be using some form of flat tappet "mechanical" lifter. The 0.300" taller boss does not matter. None of my suppliers makes a 0.300" taller lifter that I am aware of, nor have I seen the need. There should be no problem with pushrod clearance, but check it anyway. It will require full preparation, just like a GM block. You should have the dimensions checked, though it will likely not require blueprinting of the lifter bore or cylinder bore location. It probably will require the main bores to be lightly honed for size, and it will almost certainly require decking (make sure it is square, it probably will be, and that whoever does it keeps it that way). The shop that preps it better know exactly what they are doing with a Dart block, from experience, or the rings will never seat, you'll have blow by and oil consumption problems. I see that happen a lot. __________________ Alan Roehrich 212A G/S

08-01-2012, 02:05 PM	#3
Arnold Greene Member Join Date: Mar 2003 Posts: 131 Likes: 0 Liked 3 Times in 2 Posts	Re: dart big m block You will most likely need to change the front springs. The Dart 396 block weighs 290 pounds! Ask me how I know. __________________ Arnold Greene IHRA/NHRA 2420 A/S, B/S

08-01-2012, 03:11 PM	#4
steve4speednova Junior Member Join Date: Jul 2009 Posts: 57 Likes: 0 Liked 0 Times in 0 Posts	Re: dart big m block thanks guys for the reply. I,m useing 1965 #962 block now, with 4.150 bore. it makes about 560 hp.to the rear wheels. what would the dart block be worth in power ?

08-01-2012, 03:34 PM	#5
richie 2 Senior Member Join Date: Feb 2009 Posts: 924 Likes: 328 Liked 160 Times in 74 Posts	Re: dart big m block are they gaining any poularity for SS applications?

08-02-2012, 10:44 AM	#8
carl hinkson Member Join Date: Feb 2007 Location: NORTHEAST Posts: 287 Likes: 1 Liked 18 Times in 10 Posts	Re: dart big m block I CNC machine alot of Dart big -M blocks and this is what useally needs to be addressed. Some block notes: I deck all of them to a finished number depending on gasket & desired piston height Block needs to be honed with a plate or bored & honed depending on bore Bottoms of bores need to be chamfered Most need the lifter bores honed, at the least checked Most need line honing All pipe threads need to be retapped Oil return from fuel pump cavity needs to be done Core plug holes need deburing CHECK THAT THE DISTRIBUTOR GEAR DOES NOT CONTACT THE BLOCK BY THE CAM.