199 performance build

I'm pretty sure you're going to have to use an early 80's or newer block. When the Eagle line came out, AMC added bosses for the brackets that locate the front axle.

Wrong assumption on the pushrods and cam using a 4.0L head with an early 199/232 block. The cams are identical as far as the positions of the lobes and bearing journals, and they will interchange from 64-06. I used a 258 cam in my 4.6L stroker for a while. The only difference in the cams is that a 4.0L specific cam won't have a fuel pump eccentric on it (4.0L block has no fuel pump hole/boss, have to use electric). The shaft head has the rockers in the same position as the bridged rocker heads. The only difference is the deck height and the rocker ratio. The shaft rocker has 1.5:1 rockers, bridged has 1.6:1 rockers. Pushrods need to be checked for length due to the difference in deck height.

For what you're doing the first thing I'd do is take a bare 72+ block to a machine shop and ask them what they think about decking it 0.125". Might be doable. Check with the local Jeep guys -- you can probably find a block cheap or free, might have to take the whole motor.

The problem with using V-8 rods is the big ends might be too narrow, you'll have to check. Running a bit narrower rod shouldn't be too big a deal, the V-8 guys run narrower Chevy rods in drag motors. Don't think I'd do it in a road race motor though.

Another solution would be to order custom pistons with the pin height 1/8" lower. Unless there's a rod just the right length you will have to have custom pistons to match the pin height to the rods anyway. May as well cut your losses and just order pistons to fit the stock rods.

Did you talk to TomJ about that T-5 adapter? Won't help if you want to run an auto though. And why worry about running the stock transfer case? If you're doing this much work you can locate a good transfer case to match whatever trans you use. The only difficulty would be if the t-case has the front shaft on the driver's side instead of passenger side -- that won't do in an Eagle! I wouldn't worry a lot about the axle support boss. It won't be to hard to fab up a support if necessary, but a 80+ block would be the best idea.

I think the head bolt holes would be deep enough, and it wouldn't hurt is they were 1/4" shorter.  Hmm... you're right -- the deck of the block is 1/4" taller on the late model, not 1/8". Still, the deck might take it -- won't hurt to check. I was going from memory instead of checking again...

Understood on the transfer case. Custom pistons will be cheaper than custom rods. Egge Machine can put the pin wherever you want it. You might want to talk to 74Bubblefender about pistons. He gets custom pistons for the 4.0L. Dropping the pin 1/4" might be a problem, but I don't think so. He will know more about that though, or who to ask. If you find a rod that will work you may still need custom pistons to get the pin where you need it. 

Wasn't there an Indy Car in the late 60's using a 199 ci 6-cylinder AMC turbo engine, i'd imagine any info you could find on that might prove helpful.

72AMX wrote: Wasn't there an Indy Car in the late 60's using a 199 ci 6-cylinder AMC turbo engine, i'd imagine any info you could find on that might prove helpful.

It was one of the Barney Navarro engines.  TomJ here on the forum has one of those engines and I think there is info posted about it on his website.  www.wps.org     Joe