Hey all, I'm in the process of throwing together a bunch of parts that will end up being a 634 Gen Vll. I was wondering if anyone here has built one up and has any advice to share from lessons learned.

I've got a Dart Big M Gen Vll block bored out to 4.610. Ross Racing pistons with a 18cc dish will keep me in the mid 9's on compression. That number will depend on where the chambers of the Raylar heads end up after being un-shrouded. 2.300 intakes and 1.880 exhausts are being installed. After popping out the seats, the floors were welded to raise them as the first cut on an intake seat went into the water jacket. After port and polish work, they should flow in the 400's. The bottom end consists of Callies H beam (6.660) rods and an Eagle 4.750 stroker crank. I've got a Raylar intake that will be modified to run a 102mm TB and new XX Raylar cam on the way. Larry thinks I'm crazy, but I want to put an adjustable valve train on it and stud girdles, just can't drop the old school habits. I plan on welding up the top center valve cover hole and drill and tap a new one for standard taller valve covers.

Does anyone out there in 8.1 land have an engine harness for a drive by wire version? I need to make a dyno harness. Thanks in advance for any information you can share.

 

This sounds fun. I don't have much advice to offer on the the Gen-VII BBC platform. As far as I know, all years of all 8.1's from the factory had ETC. Are you going to dry sump this? I think that rotating assembly is going to like higher oil pressure and I think a high-pressure and volume pump would give you problems chewing up the oil pump drive gear.
The plan for the valve covers sounds good - the Gen-VII covers are annoying short but they've got the same sealing rail as standard BBC. You probably won't need full-height BBC covers due to the deeper walls of the Gen-VII head, maybe a Vortec 7.4L covers would work. There was a distributorless version of the Vortec 454 with RPO code L21. If you're lucky enough to be able to locate a source for those covers maybe two of the driver-side one would work for you. (The passenger side L21 covers have the coil packs are weird angles to leave the 7.4L side-entry TB.)

 

Thanks for the info on the covers. I'll keep an eye out for some. I've got the Melling HP pump and I'll be changing out to a bronze gear and hope that will aleviate the gear issue. All said and done using the 1.2hp per cube, I should see just north of 750hp. That should move an '06 2500 down the road.

 

 

i was thinking of doing the same with the block and im wondering what kind of price you got for the block?

 

I've been thinking more about this...
Have you considered building a conventional tall-deck Gen-VI BBC instead of using all these high-dollar Gen-VII? parts?
I think you'd have more options for parts and they would be less expensive. Especially heads. It's going to take very large rectangle port heads with big valves to feed this much displacement if you expect it to rev.
The items needed that make it possible are:
- 24x crank reluctor and timing cover conversion from EFI Connection with or without 1x cam sensor. If the timing conver is without the 1x sensor then also needed is a 1x dummy distributor.
- Cam with 1-8-7-2-6-5-4-3 firing order (you need this so the PCM trims fuel right)
- Any BBC intake manifold that supports parallel coolant flow and bypass.
- Vortec 454 water pump

If it were me I'd be going this route. I don't see the benefit to sticking with the Gen-VII platform other than it sure would be unique.

 

12554351 left valve cover L21
12554352 right valve cover L21

$70 each from GM Parts Giant.

If you wish to run a 24x system, the stock 99-00 L21 crank reluctor12552480 along with the L21 crank position sensor 10456248. The stock L29 crank position sensor will not read the 24x reluctor.

That L21 reluctor will slide right on a GEN 5/6 crank snout, use an L21/29 front timing cover to hold it, and then use a calibration from an LS1 Camaro/Firebird for cable throttle, or an LS1 Corvette if you wish to use ETC(E;ecytronic Throttle Control)

I agree with James.

peace
Hog

 

I bought the block for $2200 already punched to 4.600.

 

I thought about it but came across a Raylar equipped long block for a reasonable price. You hit the nail on the head, it's unique.

 

Hey Vulcan,

Here's another customer's 632 at the shop, when your engine comes together it should make for a real monster!