v-8 conversion

[davidyoungdoff]

I have a 78 CJ7 and I
want to convert to a V-8 from a AMC 258 i6 / 4.2l straight six. Do
motor mount locations have to change and with a 3 speed
manual, is this complicatedc? Does it require a new clutch, motor mount movements on frame?

 

[LongHorn]

There's a good chance you'll need a bigger radiator too. I never liked the factory AMC motor mounts they have a strange habit of separating completely. I used M.O.R.E. bombpruff mounts & have nothing but good things to say about them.

 

[LongHorn]

The three with red circles are different from a six cylinder Jeep.

 

[CJ]

Hello davidyoungdoff and welcome to the site!

The V8 conversion is relatively easy and is very popular. You need (as Longhorn mentioned) a new frame bracket (pass side), block brackets, rad hoses, heater hoses, exhaust, possibly some assorted wiring, flywheel, possibly clutch linkage, possibly a better radiator, throttle cable, you may need to move your Transmission mount forward or backward a bit and a few assorted odds and ends.

Just about everything you need is available in the aftermarket.

Here are another thread discussing this topic.
http://www.jeep-cj.com/forums/f2/v8-conversion-cj-5-a-722/

 

[BigDsCJ7]

I am also doing a V8 conversion now. I'm running into some trouble getting all my ducks in a row before I start. The 350 and 700R4 a got came with a NP208 transfurcase. Will this work, or will I need to get a kit? I know in the late 80's Chevy switched to a driverside drop. Please let me know what you guys think.

 

[CJ]

Are you saying the NP208 is already mated to the 700R4 or do you need an adaptor?

Novak has one for this combo... -->> Adapting the 700R4 / 4L60E to Full Size Jeep NP Transfer Cases

 

[BigDsCJ7]

Its already mounted to the 700R4. Will the whole assembly fit under my CJ7 . Its from a early K5 Blazer. Sorry for the confusion and thanks for the help.

 

[BigDsCJ7]

Im also trying to get rid of my AMC 258 i6 / 4.2l . Should I keep my Dana 300 ? Is that a better option?

 

[CJ]

Its already mounted to the 700R4. Will the whole assembly fit under my CJ7. Its from a early K5 Blazer. Sorry for the confusion and thanks for the help.

I'm not positive but I believe you should be OK. If the output for the rear is on engine center and the front on the correct side I don't see a problem. You may have to change the clocking of the Transfer Case to the Transmission though (if that is even possible).

Im also trying to get rid of my 258. Should I keep my Dana 300? Is that a better option?

Well the Dana 300 is a great Transfer Case and pretty much bullet proof under most applications (and it doesn't have a chain), it really deepens on how easy you want to make your swap... Novak has an adapter for the 700R4 to the Dana 300 also. -->> Adapting the 700R4 / 4L60E to the Jeep Dana 300 Transfer Case

 

[BigDsCJ7]

I guess the other question is what axels. Hahaha, it never ends! Thanks for your help.