I am beginning the build of a 421 SBC [4.165 x 3.875 that will produce about 725 horse with an upper limit of about 7800 RPM. In this situation. which block would you employ?

I have owned both dart little m and a world products block. The dart was imo a better block. I have not seen a shp block in person so can’t comment on that.

I have had a little m and the shp. It's hard to beat the little m, very nice block.

I have Dart and Brodix.
if you go Brodix be sure and seal bottom head studs on passenger side. mine were not blind and went into the water jacket.

ep-Brodix is a nice block though

I just put my eyes on a Little-M Sunday. Very nice product. If you can get one. Took from June order to mid October to get one for my friend. One will be used in my next build.

Curtis

Dart is offering a Little M with a raised cam now. I would go that way.

The Little M with raised cam sounds like the cat's meow.

This is a 134" raised cam, 904 bushed lifter bore, splayed billet cap, w/big block Chevrolet cam bore, 350 mains 4.185 bore Motown block we used a Callies 3.875 Magnum crank and Ultra 5.85 rods we topped off with a set of All Pro raised runners, camshaft is north of 900 lift. I've done a couple of these now for this man, this one makes a little over 100 hp more than my 750hp 427 I built around a Dart Little M block with billet caps Lunati Pro Series 3.875 crank and rods, according to the dyno pulls we made. When we ordered this block Dart didn't offer a raised cam little M, so you may wanna double check availability. But I've done a several using both and see only a small differences from the Dart Little M in comparison. One interesting thing of note is the Motown block was advertised 55mm cam at the time we ordered it, so there must have been a change in that area from the early versions, so if you see that on the net as we did be certain it comes big block Chevrolet cam bore on the raised cam block.

725hp 427 is easily had, even with a underrated set of out of the box 23 Brodix Track 1 233's, high compression. I have one that dipped in the 5's N/A 3200 lb Nova off the trailer. It has a high 5.80 in it with a little tweaking and good air. I haven't put but a handful of wide open runs on it ha ha! It's shift at 7200 rpm, the camshaft is just under 700 after lash. I did change the springs to ISKY before startup. I ended up with two half sets of valve springs to get the right spring on it for the difference in the lift between intake and exhaust lobe. If you need any further info fire away I'm fairly familiar with both Dart and Motown. Good luck

quote:

out of the box 23 Brodix Track 1 233's,

I have to say I had never even heard of the 233 version of that head until you mentioned them.I now see they even have a 245 version. Seems like they are priced as more of an upper end head compared to the budget friendly t1's.
That said, my T1's took a lot of work to not flow as well as those two heads. I'm planning on doing some work to the exhaust side this winter.

For SBC blocks I would rate them
1. Iron eagle Dart
2. Chevy Rocket
3. Little M Raised
4. Little M
5. World Products
6. SHP Dart
7. Factory Chevy.

quote:

Originally posted by Bucky:

quote:

out of the box 23 Brodix Track 1 233's,

I have to say I had never even heard of the 233 version of that head until you mentioned them.I now see they even have a 245 version. Seems like they are priced as more of an upper end head compared to the budget friendly t1's.
That said, my T1's took a lot of work to not flow as well as those two heads. I'm planning on doing some work to the exhaust side this winter.

If my Little M block were a raised cam with the bigger cam housing bore of the Motown I would have went with the Brodix T1 245, beefier less flimsy big block cam core with more lift but on the bright side it makes decent power as is, and durable to the extent of the parts in play, which are all considerations to evaluate in choosing a block. I'd definitely want a raised cam block If I were the OP, whether it be Dart or Motown. It took a couple sets main bearings to get the clearances up to snuff with this Motown block, but that's small potatoes in the grand scheme of things and fairly common standard procedure.

This message has been edited. Last edited by: Mike Rietow,

I have dart shp block in my street/strip camaro. And a dart iron eagle in my 67 Chevy II. Both are nice blocks. The iron eagle is btter for the race only. Only downside is there isnt a provision for the oil filter...you have to use a remote filter.

quote:

Originally posted by Curly1:
For SBC blocks I would rate them
1. Iron eagle Dart
2. Chevy Rocket
3. Little M Raised
4. Little M
5. World Products
6. SHP Dart
7. Factory Chevy.

Given this list you posted, at what point in HP would one consider moving to your next higher rated sbc block?

Example, if one wanted an engine that makes 700 hp NA @7000 what blocks would work well at a reduced cost and still offer longevity?

Others input to this also appreciated.

This message has been edited. Last edited by: markemark,

quote:

Originally posted by markemark:

quote:

Originally posted by Curly1:
For SBC blocks I would rate them
1. Iron eagle Dart
2. Chevy Rocket
3. Little M Raised
4. Little M
5. World Products
6. SHP Dart
7. Factory Chevy.

Given this list you posted, at what point in HP would one consider moving to your next higher rated sbc block?

Example, if one wanted an engine that makes 700 hp NA @7000 what blocks would work well at a reduced cost and still offer longevity?

Others input to this also appreciated.

This is just my opinion and I like to keep it conservative and durable. But I would say 650 Hp for Little M, 725 or so with Little M raised cam and anything over that the Iron Eagle. To me the raised cam is a big deal, you can use a cam with BBC size core and not have rod / cam clearance issues. I do not like to use small base circle cams. We used to do it long ago but better options now. I also like the blind head bolt holes on the Little M block.
To go more than 434 Cubic inches I would go with iron Eagle or rocket block because of wider oil pan rails.

At 700hp a little m sportsman or world will do just fine. The little m with all four bolt caps will work to almost whatever you want. If the build calls for longer than 3.75 stroke a raised cam really is best. The shp dart is good for less than 700hp. The stock block maybe ok to 600, maybe not. Kind of a luck of the draw there. Just my opinion yours may vary.

We have a SHP block 408 sbc I'm converting to pump gas for a guy for an extra clean straight small tire 67 chevy II street hot rod we're planning on around 625hp. Hydraulic roller camshaft, 4150 carb with an old set of Dart heads, like new condition, ported nicely. This is a 3.75 stroke Callies magnum crank 6" Ultra rods, Jesel belt,,, nice stuff. This thing had a set of 18 CFE heads on it with 500hp on a plate for a hundred laps. It made 825hp on the dyno, dominator carb. Should make for a pretty decent car show tire burner, fun to drive and a little more fitting environment for the SHP block.

Just curious on peoples thoughts. But when you talk about cranks and blocks. Witch is better. Small journal mains or large journal mains. I can see pros and cons both way. Smaller less rotating weight. Larger should be stronger.

I prefer the 400 mains on anything above a 3.75 stroke. However lots of engines are built with 350 mains the are longer stroke.

quote:

Originally posted by ts393c:
Just curious on peoples thoughts. But when you talk about cranks and blocks. Witch is better. Small journal mains or large journal mains. I can see pros and cons both way. Smaller less rotating weight. Larger should be stronger.

My opinion is 350 mains and put the strength in the cap. With the quality of the cranks now no reason for a larger main if NA.

We plan on putting Curly's hp theory to the test with a standard cam location block. Should be about 1200hp when we are done.

Curtis

quote:

Originally posted by ts393c:
Just curious on peoples thoughts. But when you talk about cranks and blocks. Witch is better. Small journal mains or large journal mains. I can see pros and cons both way. Smaller less rotating weight. Larger should be stronger.

We put together a motor out of older pro stock stuff we had, which consisted of a BBC crank with SBC rod journals. It lasted about 75 passes before breaking the crankshaft at the rod journal, the mains were fine. In the crankshafts defense, I was making about 18 lbs of boost at the time..