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 trans 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 trans though (if that is even possible).

Im also trying to get rid of my AMC 258 i6 / 4.2l . 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.