Are the L67 series I and series II block different?
 

I was going thru some information on my '92 bonneville and realized that the '92 has an L67 block designation like the newer series II block. This my not be new to you, but my question I have is this: Is there a difference between the Series i and Series II L67 block. I read that in '96 the Series II was bolted to the 4T60-E. so evidentlly the bolt patterns are the same for those. I guess the ultimate question is this: Is it possible to install series II heads, etc. on a series I L67 block? Thanks in advance for the input.

Chuck
P.S. I found my information here.
http://williamwren.com/timeline.html

From what I know.....The blocks are the same..........But I think that the bolt patterns on the heads are different?????? I maybe wrong on that....What's the difference between serie ! and Serries 2 heads?

The Series I and Series II blocks are different. Different bolt patterns for the heads, oil pans, different coolant passages, etc..
So, to make it short, they will not interchange, and the internal parts are different also.

Well I wasn't too far off

Thanks guys, will the SII still hook up to the 4t60E tranny. I know it is not as strong, but I don't think I can afford to build an engine and tranny at the moment.

What do you think most of the Series II N/a motors have behind them? 4T60E's. I believe that even the supercharged motors through 1997 had 4T60E HD transmissions behind them. The 4t60's seem to hold up well except for the very common TCC issues. If you are using an OBDII PCM to control an older 4T60E, you may have problems with differences in wiring though.

The '97 SSEi had the SII and the 4T60E. I think OBD II was on by then. If I got a pcm from that, would the wiring still be the same for the tranny or did that add more useless crap after they changed the engine? :helpsmilie:

The 4T60 seems to be a more durable trans in stock form than the 4T65. There isn't much of an aftermarket for the 60, though. Unless you go to a builder.

I have a good friend that owns a trans shop. I'll probably give him a call. He rebuilt my tranny last time and it lasted me 160,000mi. till I got rid of the car. He also cut out the shift lock between D and 2nd. Any simple ideas to beef up the tranny while I have it out anyway? Lord knows I don't want to take it out a week after I have it back in. :x

Chuck, a lot of the 4T60E's are one year-only specific to their PCM's. You could work around this I'm sure, but I wouldn't want to guess at what each model year difference is and end up with a trans that shifted like crap. I replaced the trans in my 70k mile 3800 series II 97 LeSabre, and there were two seperate 4T60E's even for my one year, depending on whether or not I had a particular "timing option WA2", whatever that was. And the 1997 only interchanged with the 1997 due to the fact that my year uses pulse width modulation to engage the TCC. Some years use a voltage on/off to engage the TCC. If you plugged an older 4T60E into my car it would probably drive like a nightmare. Used transmissions are not that expensive, I got the correct trans, with 31,000 miles on it, for $375 plus tax. I'd figure out what year PCM you are using and then get a low mileage used trans to match it.