4.0 head on 4.2 conversion
 

Hey guys,
I'm considering putting a 4.0 head on my 1984 cj7 4.2. Has anyone got
any first hand knowledge/experience of this and is it worth the effort? I
will continue to run the carb set up for a while, till I can gather enough
nickels to buy the fuel injection package. I'm looking for more hp through
better breathing characteristics. Any input is welcome....
Thanks, Charles

Re: 4.0 head on 4.2 conversion
 

I did the conversion myself. There are a few good links to how to's you can
find on Google. Bill ------ has a link I'm sure. I got the head from a
rebuilder who only wanted an inline six head in return as a core. So I gave
him my 258 head and I didn't lose for that. I also got a header for $150
that, while its not a boorla, it works fine. Lastly I had to have a custom
headpipe made to fit between the header and the muffler. Duotone in PB took
care of that for about $50. The difference was incredible. I gained a ton of
power and gas mileage also improved. I used JB weld and packing peanuts for
the coolant passages and after 18 months everything is running fine. The
jeep has seen daily driving and even a cross country trip last October.
Would I do it again, absolutely. My only difficulty I had was with rods.
Just be careful with the pushrods. I had guys tell me I can use the 4.0 rods
and others said no I should use 258 rods. I had to have a custom set made.
Fortunately, I was living in San Diego at the time and Crower cams took
excellent care of me. If you want to know how to measure for them I can help
you there.

"Ervin Charles" <charleserv@charter.net> wrote in message
news:iFScf.1241$Ae3.869@fe06.lga...
> Hey guys,
> I'm considering putting a 4.0 head on my 1984 cj7 4.2. Has anyone got
> any first hand knowledge/experience of this and is it worth the effort? I
> will continue to run the carb set up for a while, till I can gather enough
> nickels to buy the fuel injection package. I'm looking for more hp through
> better breathing characteristics. Any input is welcome....
> Thanks, Charles
>

Re: 4.0 head on 4.2 conversion
 

I did the conversion myself. There are a few good links to how to's you can
find on Google. Bill ------ has a link I'm sure. I got the head from a
rebuilder who only wanted an inline six head in return as a core. So I gave
him my 258 head and I didn't lose for that. I also got a header for $150
that, while its not a boorla, it works fine. Lastly I had to have a custom
headpipe made to fit between the header and the muffler. Duotone in PB took
care of that for about $50. The difference was incredible. I gained a ton of
power and gas mileage also improved. I used JB weld and packing peanuts for
the coolant passages and after 18 months everything is running fine. The
jeep has seen daily driving and even a cross country trip last October.
Would I do it again, absolutely. My only difficulty I had was with rods.
Just be careful with the pushrods. I had guys tell me I can use the 4.0 rods
and others said no I should use 258 rods. I had to have a custom set made.
Fortunately, I was living in San Diego at the time and Crower cams took
excellent care of me. If you want to know how to measure for them I can help
you there.

"Ervin Charles" <charleserv@charter.net> wrote in message
news:iFScf.1241$Ae3.869@fe06.lga...
> Hey guys,
> I'm considering putting a 4.0 head on my 1984 cj7 4.2. Has anyone got
> any first hand knowledge/experience of this and is it worth the effort? I
> will continue to run the carb set up for a while, till I can gather enough
> nickels to buy the fuel injection package. I'm looking for more hp through
> better breathing characteristics. Any input is welcome....
> Thanks, Charles
>

Re: 4.0 head on 4.2 conversion
 

I did the conversion myself. There are a few good links to how to's you can
find on Google. Bill ------ has a link I'm sure. I got the head from a
rebuilder who only wanted an inline six head in return as a core. So I gave
him my 258 head and I didn't lose for that. I also got a header for $150
that, while its not a boorla, it works fine. Lastly I had to have a custom
headpipe made to fit between the header and the muffler. Duotone in PB took
care of that for about $50. The difference was incredible. I gained a ton of
power and gas mileage also improved. I used JB weld and packing peanuts for
the coolant passages and after 18 months everything is running fine. The
jeep has seen daily driving and even a cross country trip last October.
Would I do it again, absolutely. My only difficulty I had was with rods.
Just be careful with the pushrods. I had guys tell me I can use the 4.0 rods
and others said no I should use 258 rods. I had to have a custom set made.
Fortunately, I was living in San Diego at the time and Crower cams took
excellent care of me. If you want to know how to measure for them I can help
you there.

"Ervin Charles" <charleserv@charter.net> wrote in message
news:iFScf.1241$Ae3.869@fe06.lga...
> Hey guys,
> I'm considering putting a 4.0 head on my 1984 cj7 4.2. Has anyone got
> any first hand knowledge/experience of this and is it worth the effort? I
> will continue to run the carb set up for a while, till I can gather enough
> nickels to buy the fuel injection package. I'm looking for more hp through
> better breathing characteristics. Any input is welcome....
> Thanks, Charles
>