Engine conversion on my 7

[redrussell]

I am building my 79 CJ7 and it has a very tired factory AMC 304 /T-150 /Dana 20 combo in it now. It still runs and drives and it is my daily driver but it needs work. I have elected since I have all these parts that a chevy drivetrain is going in. I have a 350hp 420ft-lbs SBC 350, why not drop that in. I have the complete TBI setup with complete harness off a 92 GMC pickup. SM465 off my early 80s 1-ton donor truck and I have a Dana 300 I was given. My axle gear ratio still hasn't been decided but it ranges from 4.10 up to 5.20's is what we are thinking. Leaning towards 4.88

Now to add to what else I have... I have a T-18 /Dana 20 combo off my 79 J20, I have the 205 t case off the SM465, I have a 208 off my 78 Suburban I had, I have the entire drive train off a 84 Wag(from Uncles build). These are all other parts I am kicking around on the build.

My original build plan was this though. 350 with the tbi, that is decided on so use the SM465 since it bolts straight to it and I don't need to spend any money to pair that up. Build the Dana 300 since it is quite and reputable at being strong. Put the teralow gear set in it and upgrade the output shafts. Adapter from advance adapters costs me roughly $580 with a few extras. The gear set and full rebuild I already sourced will cost me just under $1,100 with everything I need. So this setup is costing me roughly $1,700 so add $300 for new mounts and misc parts and I am lookiing at $2,000. if my math is right with the tranny low of 6.54, Tcase 4.1 and gears at 4.10 I would have a 110 crawl ratio roughly.

Other option that would work is use the T-18 and the Dana 20 and get adapter to the 350, that costs about $480 for the adapter and then I have the clutch linkage brackets to build as well and not having the low gears in the t case. T-18 with granny low of 6.54 t case at 2.0 and gears at 4.10 only gives me a 57 crawl ratio. Or run the SM465 and use a 205/208 doubler kit for the GM drivetrain. That is long though and would leave me with a very very rear short drive shaft and add a bunch of weight. Just looking for peoples thoughts and opinions on this build. I think no matter what build I do I have to get new shafts front and rear.

 

[Old Dog]

Since your worried about your crawl ratio I assume you are making a rock crawler rig. If so I think that engine might be a bit much as you will be running low RPM's most of the time. A closer to stock engine might be better.
I would use the Dana 300 to keep things as short as possible. From what I hear JB makes a better set of gears than teralow. JB Conversions, Inc.
Don't forget you are going to need some stronger axles than what came in the cj. What tires are you planning on?
There is also going to be a lot of nickel, dime stuff along the way, so you might want to bump up the budget a little.

 

[redrussell]

That is what the engine did at the crank, I will lose roughly 20% of that spinning the tranny and once I put all the accessories on the front it will suck more off. I have a Dana 44 and d60 combo I will be dropping in once I get the funds for the complete builds on them. I had posted a build thread on here but for some reason I can't get "approved" to have it put on the forum.