BOP / Chev case differences?

[S10xGN]

Hi All,

I'm going to going to go with a "CZ" MCSS tranny in my LS-1 powered '47 Ford coupe, but only 4 bolts will mate up between the LS motor and the Chevy case. I'm told the BOP case has a few more bolts that make up. I plan on rebuilding the tranny, so if I find a junkyard BOP case, will there be any problem with the guts swapping in?

Thanks!

 

[bison]

Hi All,

I'm going to going to go with a "CZ" MCSS tranny in my LS-1 powered '47 Ford coupe, but only 4 bolts will mate up between the LS motor and the Chevy case. I'm told the BOP case has a few more bolts that make up. I plan on rebuilding the tranny, so if I find a junkyard BOP case, will there be any problem with the guts swapping in?

Thanks!

The CZ transmission should have both bolt patterns, BOP and Chevy.

 

[S10xGN]

Sorry, that's what I get for going by memory! I pulled the tranny off yesterday (to put the engine on a stand) and found the code to be "CQ" and there are 5 bolts that line up, not 4 as previously stated. That makes the 2 pairs on each side around the dowel pins (4) plus the single bolt just north of the LH pair, is that gonna be enough?

 

[bison]

Sorry, that's what I get for going by memory! I pulled the tranny off yesterday (to put the engine on a stand) and found the code to be "CQ" and there are 5 bolts that line up, not 4 as previously stated. That makes the 2 pairs on each side around the dowel pins (4) plus the single bolt just north of the LH pair, is that gonna be enough?

I just put a CR case in one of my buicks yesterday and it came out of a Chevy. You should be all set with the CQ in a BOP or a Chevy, unless someone removed the tag from the CQ (which is highly unlikely)and put it on an 82 200-4R. In 82 the 200-4R had single patterns.

 

[S10xGN]

OK, but the rear of the LS-1 is a strange cookie! As seen in the engine pic, the red arrow points to the 5th bolt that will make up. The green arrow shows the lack of a bolt on the PASS side. The top bolt is missing completely on the tranny case as seen in the tranny pic.

Later!

 

[CTX-SLPR]

I believe most LS1 guys run it without that bolt in there. I'd just use good bolts at all positions with accurate torques and call it good.
On a side note, LS2 blocks have a boss for that bolt but its not drilled. Gen IV truck blocks still use a classic Chevy pattern and have that hole drilled and tapped. The only other thing you could do is get a welder to add a piece of billet to the area and then drill and tap the billet, just make sure its a good welder.

 

[bison]

My bad. I missed the LS part of your first post. Im not sure about the back of the LS blocks. I have no experience with them.

 

[chris718]

the 5 bilts will work.BUTyou must trim the case at the 12 oclock position for clearance,look at the back of the motor and youll see what im talking about

 

[S10xGN]

the 5 bilts will work.BUTyou must trim the case at the 12 oclock position for clearance,look at the back of the motor and youll see what im talking about

Well, this would explain the hairline gap at the top when I bolted up the tranny! Thanks for the heads-up Chris, luckily I just had the bolts finger-tight and not cinched down!