[ryeguy2006a]

After seeing the that new ZZ632 motor blasting all over the internet, I noticed that it had a 58x crank and 4x cam signal after getting over the shock of 1k HP. That got me looking around and found that GM has a part number 19370171 for this timing cover that says it works with MarkIV blocks. Is that a direct replacement though? Will that work with a standard BBC oil pan? I see that there are a few mounting points that are different.

19370171 BBC 58X Conversion Kit

Convert your Big Block Chevrolet to Coil on Plug Ignition with 19370171 Kit from SDPC

sdparts.com

I'm sure it's kind of a pipe dream, but I was thinking it would be cool to upgrade my Dad's 496 to run full sequential EFI. This would be a great kit do to it with if it would work with MarkIV blocks. He's running a 496 with a Dart Big M block.

Thanks,
Ryan

 

[RatchetRay]

Listing this as working on MK IV blocks must be a typo, no way this same part number works on them all due to the 1pc vs 2 pc mains.

 

[ryeguy2006a]

I called them about an hour ago and the guy I spoke with said they have had customers report that it works on MKIV blocks, but wasn't sure what modifications they needed to make. From what I understand, the timing covers all bolt to the blocks the same way, but it's the way that the front of the oil pan seals that is the issue.

 

[GoFast Beaumont]

I have a Gen vi block and last time I wanted to change over to this setup and required block machining. That said mayby the front of a mkIV might be doffernet

 

[ryeguy2006a]

Do you happen to have any pictures? Curious what machining would be required. I've found several people online who say that they've made it work, but none have shared any pictures.

 

[btags]

The Gen 5 and Gen 6 timing covers are different than those of a Mark IV, the Gen 5/6 timing covers have a U-shaped channel at the bottom that meshes with the opposing U-shaped oil pan surface. The Mark IV timing cover to oil pan mating surfaces are largely flat.

 

[miket1]

it won't work,,bolt pattern is totally different,,use correct mark4 cover on mark 4 engine

 

[ryeguy2006a]

Several people have interchanged the timing covers so I'm sure that they can be made to work. I'm just wondering if someone makes a hybrid oil pan that allows for the rear 2 piece seal, but recessed Gen6 timing cover to be used.

 

[ekitch]

I have a ZZ454 gen VI block, going to build a 454 EFI for my corvette. Will be using a gen IV steel crank with a seal adaptor. I didn't know this kit existed until now. What would be the benefits, is it even worth the hassle? Block machining? Possible machining of the balancer? Seems like too much work to me for a street engine. Yes the oil pans are different between the Mark IV's and later blocks. Someone like Moroso or Milodon should have made a hybrid pan by now. It is possible to graft a couple of pans together to make it work, I bet a few guys have done this. A gen VI timing cover will physically bolt onto a gen IV block but will not mate up to the old 2 pc seal oil pan. Likewise, a gen IV timing cover can be bolted onto a gen VI if you drill the extra holes, but the oil pan is still an issue. Ask me how I know.

 

[BBPanel]

I have converted my Mark IV to EFI using the Gen V/VI pan and timing cover. The oil pan was simple - grafted a Mark IV piece on the rear. For the TC, 4 of the Gen V/VI bolt holes lined up. There are 4 holes on the top of the Mark IV block and only 2 on the Gen V/VI TC and the 2 on the Gen V/VI TC don't quite line up with the block. To solve this, I tapped the TC hole boss, threaded a bolt in after cutting off the head. The outer nut is tack welded to the stud to tighten the TC against the WP, the other nut is used to snug everything down so the stud doesn't loosen up. I used a L21 24x reluctor on the crank snout and then had the back of the balancer hub machined down the thickness of the reluctor (~0.070" as I recall). I'm using a 1x Vortec distributor. I'm also using the 96-00 GM L29 fuel injection manifold and a Holley Term X Max harness and ECU. Last pic is where I am sealing the TC to block before installing the WP.

One thing I discovered since doing this. Apparently, there are 2 different Gen V/VI TCs. They both have the CKP sensor casting but one has a hole in it and one does not. I used the cover w/o the sensor hole and drilled it out. I have never been able to determine if there is a different p/n for the 2 TCs but drilling it out was difficult and I would find the TC already with the sensor hole in it.

I have not fired the engine yet - body is off frame while I've been updating the suspension and sandblasting the body for primer. This is not a Chevelle but a '56 Chevy Panel.

My electronics knowledge is limited but here is a suggestion - if one could use the Holley dual sync distributor (which is hall effect) with a 0411 GM PCM this conversion would be a snap. I don't know if that particular combination will work and no one I have asked seems to know the answer. A relatively cheap solution if it can be made to work - might be worth investigating.

 

[RatchetRay]

A simpler solution for the distributor would be to use the Gen VI distributor(find an aluminum one and not the plastic one) for the cam signal, a dust cover is available from eficonnection.com to eliminate the cap. Used with the L21 crank reluctor and crank sensor, you can have the 8 coil setup using the 411 LS PCM.

 

[ekitch]

I have converted my Mark IV to EFI using the Gen V/VI pan and timing cover. The oil pan was simple - grafted a Mark IV piece on the rear. For the TC, 4 of the Gen V/VI bolt holes lined up. There are 4 holes on the top of the Mark IV block and only 2 on the Gen V/VI TC and the 2 on the Gen V/VI TC don't quite line up with the block. To solve this, I tapped the TC hole boss, threaded a bolt in after cutting off the head. The outer nut is tack welded to the stud to tighten the TC against the WP, the other nut is used to snug everything down so the stud doesn't loosen up. I used a L21 24x reluctor on the crank snout and then had the back of the balancer hub machined down the thickness of the reluctor (~0.070" as I recall). I'm using a 1x Vortec distributor. I'm also using the 96-00 GM L29 fuel injection manifold and a Holley Term X Max harness and ECU. Last pic is where I am sealing the TC to block before installing the WP.

One thing I discovered since doing this. Apparently, there are 2 different Gen V/VI TCs. They both have the CKP sensor casting but one has a hole in it and one does not. I used the cover w/o the sensor hole and drilled it out. I have never been able to determine if there is a different p/n for the 2 TCs but drilling it out was difficult and I would find the TC already with the sensor hole in it.

I have not fired the engine yet - body is off frame while I've been updating the suspension and sandblasting the body for primer. This is not a Chevelle but a '56 Chevy Panel.

My electronics knowledge is limited but here is a suggestion - if one could use the Holley dual sync distributor (which is hall effect) with a 0411 GM PCM this conversion would be a snap. I don't know if that particular combination will work and no one I have asked seems to know the answer. A relatively cheap solution if it can be made to work - might be worth investigating.

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Nice custom work there, especially the oil pan! That doesn't look too easy to me. I assume you will be using the LS version of the Holley Terminator X max. You could have gone with a single coil instead of the LS style coil on plug, it would have been a lot easier. I wonder if it is worth it to go coil on plug and how much extra power is made. Also about machining the balancer, would this create any structural integrity problems or the design of the balancer?

 

[BBPanel]

Nice custom work there, especially the oil pan! That doesn't look too easy to me. I assume you will be using the LS version of the Holley Terminator X max. You could have gone with a single coil instead of the LS style coil on plug, it would have been a lot easier. I wonder if it is worth it to go coil on plug and how much extra power is made.

The oil pan wasn't as hard to do as I thought it was going to be. Yes I have essentially a BBC-LS1. The only mod I made to the harness was to lengthen the CKP wiring. I lengthened it, wrapped it in braided RF shield and covered it with Nomex.

 

[ekitch]

The oil pan wasn't as hard to do as I thought it was going to be. Yes I have essentially a BBC-LS1. The only mod I made to the harness was to lengthen the CKP wiring. I lengthened it, wrapped it in braided RF shield and covered it with Nomex.

I am curious as to how this motor will come out. I think it will make a ton of torque with that marine style manifold. Let us know how it runs. Any more details about this motor? size, heads, cam?

 

[BBPanel]

I am curious as to how this motor will come out. I think it will make a ton of torque with that marine style manifold. Let us know how it runs. Any more details about this motor? size, heads, cam?

Its 460 ci, 049 heads, hyd roller 212/[email protected], 0.510/0.510 lift, 114 LSA. Its not strictly a marine intake - was also used from 1996-2000 in trucks. But yes should make a lot of torque - estimate 350 hp and 500 lb ft - good for a heavy cruiser.

 

[Jimmymtfan19]

What oil pan gasket did you use? And will it seal on a mark 4 block

 

[BBPanel]

What oil pan gasket did you use? And will it seal on a mark 4 block

I used the respective one-piece gasket for each pan and spliced/butted them together.