Hey guys new to the thread.... My 4.2 started knocking on me last night.... 67,000 miles.... Came as a shocker to me just bought it about two months ago and I'm having a hard time finding a low mileage 4.2. Wondering if 4.2 to 4.6 was same bellhousing bolt pattern
Thanks

 

The bell housing patterns are different.

 

If you have an m5od, a 4.6 from a manual will bolt up. The autos will not. The 4.6 m5od combo is a little harder to find though.

Only 67k on your 4.2? What year is it?

 

No it won't. The 4.2 uses the old Windsor bolt pattern, the 4.6 uses a different modular bolt pattern.

A 4.6 swap is possible, but you would also have to swap the transmission, regardless of whether it's a stick or auto.

 

Really? I didn't know that. My mistake. So the m5od has different bolt patterns for the same transmission??

 

Yep. Windsor pattern for the 4.9 I6, 302 pushrod V8, and 4.2 V6. Modular pattern for the 4.6 V8.

https://en.wikipedia.org/wiki/List_o...using_patterns

 

Now I know! Thank you.

 

yeah its a 97 single cab long bed... truck is in very good shape.. when I got it it had 67k now has 69k.... from what I read its a common problem with 97 and 98 4.2's.. im debating now what to do.. I called around and motors are going for around 800 with high miles.. rebuild or swap with 4.6

 

We're the gaskets replaced? 97's were known to hydrolock.

 

no not that I know off. I was actually looking that up this morning.

 

i actually just found a whole truck 98 single cab long bed 4.6 stick combo i can pick up for 900 bucks

 

has anyone done a full on 4.2 to 4.6 swap

 

Shouldn't be a problem if you have the 4.6 ECU and wiring harness.