Quote Originally Posted by twoll86 View Post
unless i am mistaken ( which i could be since im new to this engine) the blocks are the same
Sadly, they are not. There's a reason 3000GT owners have to import JDM Debonaire engines when they want to go to 3.5L swaps, rather than scavenging engines out of Montero SRs. And that's just going from 72 DOHC to 74 DOHC. It gets even worse with the old 12V engines vs the newer stuff. This explains a lot of it: http://www.wrenchjockey.com/Webpages/6G74swap.html

You can't even use a newer 3.5L or 3.8L in a 3000GT because of all the differences in engine block bosses and oil pump bracket issues. That stuff isn't AS bad on the trucks, but it's still a concern. Accessory brackets and motor mounts mostly.

So while the engines are a very similar family, there are a ton of differences. Enough to make this far from a drop-in swap.

This is another good example: http://www.4x4extremesports.com/inde..._3.0_3.5-6.php

That guy was going from a Montero Sport 3.0L to a Montero Sport 3.5L. Same truck, with both engines being offered from the factory, and only a couple model years separating his truck from the donor truck. And he still had to modify a ton of stuff to get it to physically fit. Last I checked, he never got the ECU working quite right.

I'm not saying there's no good info there. All I'm saying is to research VERY carefully, because there's a TON of bad info on the internet. As a very simple example, I read on this board where people were talking about what seats are 'bolt in' for a Mighty Max. Turns out, none of those people had ever seen how the floor pan of a 4x4 is different from a 2WD. Because of that, I'm stuck with seats I can't use without some serious modifications. And that's just silly seats. Imagine how much people have gotten wrong about something as complex as engines!

Just be very careful. I know of 3 distinct and mostly incompatible versions of 3.0L "6G72" alone.

I've got some high hopes about putting a 6G75 into my truck, but one thing I've learned over the past few months is that virtually all of it will be custom. One thing I wanted to do was install a 6G75 engine management system onto my 72 for testing, and I can't even do that. There's no place to install most of the sensors I need. The mounting locations just don't exist on a 12V 6G72, even though it's allegedly the 'same block' and 'ALL cylinder heads within the 6G7x family will swap between blocks.'

There's a ton of small detail differences, and it's those details that'll kill your project if you're not prepared for them.