Heads-what should I use 3.8 or 4.1 ???

[turbojack]

I scored a low milage 4.1 to replace my blowen 3.8.Its a 1985 with 25506293 heads.Im planing on doing home port job,so the question is should I use the 4.1 heads or the 3.8 (8445) heads.What is the difference between them?Also cyls have very little wear,are the stock pistons ok to use?I`m looking to build this to go mid 13`s (for now)?Any Info will be appr.,thanks

 

[HOTSIX]

Well - I dont know about the 4.1's or 3.8's...but I can help with the home port job.

I am just putting the finishing touches on a set of stock 8445 heads for my GN. I have pics at the address in my signature. I also included pics of my intake porting as well.

Feel free to check 'um out.

I have more to add that I just took....stay tuned.

 

[cool 84]

If the 6293s have bridged water ports on each end, you can use them. If not, use the other heads. The 4.1 is just as strong with one exception, the pistons. I've looked at them and they have the steel inserts and look very much like the turbo pistons. The only problem is I don't know of anyone who has tried them with a turbo motor. I would think they would be safe in the 13s but who knows what would happen if there was a little detonation.

 

[cool 84]

I forgot to mention, I believe the 6293 heads use a different thread for the accessories so you will have to use the bolts that came with the motor. I don't know for sure because I haven't gotten that far yet.

 

[b4black]

They quit making the 4.1 in 1984. 8445 heads came out in '83, so you probably have an '80-82 4.1 motor. You may want to check into the oiling passages. I believe they were enlarged in '83 and on.


There are no differences in 3.8 and 4.1 heads of the same year/casting #. In general, the later (higher) the casting number, the better; Evolution.