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I can assemble the engine ( I have been hot rodding for 30 years) but I am not an engine designer. So I hope you are right and that the Dart block only needs a hone and then assembly of my choosing of stroke. I have read on engine builder sites that they do extensive machining. I wouldn't know what to ask for.
I would have everything double checked on the Dart block rather than just hone and assemble. The cooling jackets will be full of stuff flush those out real well
Did a 408 build 2 yrs ago with their Little M block I was impressed, worlds better than the GM block. Super strong piece and some nice improvements everywhere you looked.
Have a virgin bore 509 block not sure I want to build it the webbing just cant take (I feel ) what Id want to throw at it.
That larger bore sure wakes these up though. Sound kind of like an old school 396BBC
Sounds like building the Dart SHP might be the ticket. it has a lot of flexibility on what I can do with it, meaning how much do I want to spend. Reliability is a very big issue for me, I only want to do this once and enjoy it.
The Dart SHP is better than a stock block because it is heavier and stronger. thick cylinder walls. It is out of the box ready for stroker 3.750 crank shaft. I spent 6 hours of grinding and cleaning for an 3.875.
other than the honing. You have to install all the dowel pins. timing cover, head gaskets, bell housing. You have to find a passenger side dipstick pan. You also have to remove all oil plugs like the rear of cam... and clean out left over filings from machining. I also ran it through a sonic cleaner and dried and mask for painting
tjhphoto: Makoshark has a very good deal on some things you're probably going to need. If I was building another small block motor right now I would snap up these parts. I might anyway if you don't want them first.
Because of the hardness of my Dart block, my builder had to send it out to be honed. Just an FYI incase you were thinking you could just finish hone at home. I bit the bullet buying the Dart block, but it came as a solid foundation for my build without the gamble of spending the $ on a used block and then spending more for sonic checking the cylinder walls to make sure the block is good enough before spending even more on all the machining to true the surfaces. The Dart = peace of mind for me.
With that being said, the 4.125 400ci block is what I would start with. Then look at rotating assemblies, many times the price is close between the different strokes allowing for stroked 400 which now enters the BB cubic inch area. The Dart (3.875) and Motown (4.0") blocks also allow larger strokes without clearancing being required like stock blocks.
tjhphoto: Makoshark has a very good deal on some things you're probably going to need. If I was building another small block motor right now I would snap up these parts. I might anyway if you don't want them first.
tjhphoto: Makoshark has a very good deal on some things you're probably going to need. If I was building another small block motor right now I would snap up these parts. I might anyway if you don't want them first.
For what it's worth, I think the aspect often missed is not only how much power, but how often and to what durations will you be spinning your motor to make this power. I just did the Dart SHP route for my 400. I opted to maintain 5.7" rods, stock 4.125 bore, and 3.75 stroke because it's a street car and I wanted to make great power yet leave some on the table, in the interest of reliability, simplicity, ease of maintenance and longevity. Here are some tips passed on by my shortblock builder. > 5.7 rods keep all piston rings out of the pin area, like factory engineering; 4.125 bore allows more rebuild opportunities; > 3.75 stroke can lead to minor costs like oil pan selection but the selling point here was that it would require clearancing con-rod big end bolts and/or a smaller base circle cam (at least in the SHP and, as far as I know, factory blocks) To each his own, but I chose a compromise.
The SPH is approx $1500, but is basically ready to go minus final hone so factor in any machining required for a rebuild as it will offset this a bit. The primary oiling aspect is really cool, but I don't think necessary unless building a racer. The heavier cylinder are casting and improved water jackets are really only significant improvements over the factory 400ci design. Most of the research I did indicated that one of the greatest design attributes of the sbc was its oiling/cooling capability.
I would look at a factory roller 350 block for either a 350 or 383. If money permits, I would look at SHP or GMPP for a 400. Perhaps a power adder on a stout 350? If your goals are greater, look at the bigger Darts or Motown.
r,
Rob
The way I understand it is that main priority oiling & splayed 4 bolt mains are added benefits. I went with 6" rods on mine. Rod length seems to be an ongoing debate though.
I can assemble the engine ( I have been hot rodding for 30 years) but I am not an engine designer. So I hope you are right and that the Dart block only needs a hone and then assembly of my choosing of stroke. I have read on engine builder sites that they do extensive machining. I wouldn't know what to ask for.
You might consider just buying a new short block. A new 434 sbc will run you $3500 assembled.
the racer series kits are around 4200 bucks, but you need to assemble yourself. if you want it already assembled it is a few hundred more. They include a dart aftermarket block.
Have a virgin bore 509 block not sure I want to build it the webbing just cant take (I feel ) what Id want to throw at it.
What year casting? GM lightened 'em up by 15-18lbs around '76 or so. I just found a '74 in a barn, 509 casting. Claims from those who build a lot of 400's is that this is the "holy grail", strongest of the 400 blocks ('70 - '74 509 casting).
I sure hope so, I plan to wail on it like I stole it from Harbor Freight!