Corey, I think you have to ask yourself why you would be doing the swap? If your Series I runs fine and you are OK with your current performance level, then I'd say the answer is not, not worth the time and money. But if you are not satisfied with your Series I performance or general engine operation/condition, it makes more sense to go Series II if you are planning to swap anyway. Of course that may depend on the cost difference, and your own ability to do some of the actual swap work. If you have to pay someone to do a lot of this job, it may not be what you want to do. Don't do the swap just for the hell of it, unless the cost is not a concern. I say, if it ain't broke, don't fix it, but if it IS broke, why not make it better?

My opinion is, swap to Series II only if you really plan to take advantage of the aftermarket support (aiming for 13s or better). Otherwise, it's not worth it. Rivman, who is quite knowledgeable and mechanically experienced, will be the first to tell you its not an easy job at all.

Lots of the bells and whistles are not going to work if you do the swap. It's seems to be a bigger PITA than what one might think. MY QUESTION IS...Do they make a piggyback for the ECU that will work with our Series I that would allow for "some" tuning??

Hiya guys.. Great thread..

I've done a few swaps. One was a 90 B'ville retro fitted with a 97 L67 and trans one of the others was a B'ville (NA) to SC.

As the others have outlined, it can be done cost effectively if you are doing most of the work yourself/friends. Otherwise it can be cost prohibitive. With the right tools and proper research up front it's rather easy and only time consuming. My thoughts are also 100% on swap if the reasoning is right.

On the last swap I did the car drove in from Plattsburgn NY (~5hours away) we put a fan on the engine to cool it and got to work at 7pm. With much goofing off it took four guys until 5am when we had the car running again with a new heart and legs.

Research is the key here. Know the systems and the wiring changes needed. Make a patch cable from two junkyard wiring harnesses instead of cutting and splicing. An OBD2 pcm can be programmed to ignore vats, most of your inputs to the dash are identical. It's a matter of labor.

Here's a teaser of the 90 B'ville swap. This one was a when time allowed project.

can you give me some tips, i want to have a reasonably quick car, i want mid to low 14, its not fast but quick. quick would a series 2 be better for me or should i stick with series 1. as for mods, i dotn want to do like a full blown engine like just valve train, cam roller rockers ECt. FWI pulley, exhaust and thats about it, i can get a 60K or less series 2 for anywear from 500-900

I think if you do all the basic mods to a Series I, it would be plenty quick. Definitely in the mid 14s. Think of it as money/time saved on a Series II install - to be used for lots of Series I mods. A bonus of a Series I is that high-pitched scream you get from using tiny pulleys.

Hi evereyone. I'm new to this forum. I just recently bought a 95 Riviera this past monday and decided to do a little reserch on it, and I ended up here.I didn't even know there where guys out there supping up 3800s. I had no Idea the damn thing is as quick as it is. Actualy I only bought the Riv because the cops took my Caprice and I have to get back and forth to school. Istill plan on buying another price but I think I'm gonna end up keeping the Riv. If its gonna be part of the squad it cant stay stock. I was reading about the differences in the series I and series II. I was wondering has anyone tried putting the series II heads on the Series I block. i read that the series II heads increase compression. If the series II heads will fit I want to purchase the whole top end of a series II L67 (cyl. heads, lower intake, M90, etc.) port and polish it and slap it on my series I block. any feedback welcome.

Welcome! I don't think you can swap those parts from a series II onto a series I. You'd be better off doing a Series II conversion, getting a full engine/trans, PCM and harness from a later model if you really want to go that route. The Series II have more power and more mods available, plus if you really want to mod it's easier to reprogram an ODB-II PCM.

That said, there is some stuff you can do to a series I so see what fun you can have there before considering a more complicated series II swap.

Welcome to the site! Good luck with your Riv!
-Derek

the series 2 engine parts will nto bolt up. pushrod length, deck hieght, cam , etc. are all diffrent. .


If you really want to do a series 2 I would look up rivman. He did a full series 2 swap.

is push rod length the only problem because if thats the case i could just find out the specs on them an get new ones that'll fit. I would just go ahead and do something simple like a pulley swap but i dare to be difficult. It makes life more intresting.

I've seen side by side head comparisons, and seems to me there are significant differences, not just push rod length.

Actually length of the pushrod isn't as big of a problem as the angles.

S1 has that one backwards cylinder and S2 does not. Otherwise IIRC (I've seen pics side by side) they are reasonably similar...but not quite enough to ever make it work.

A swap would be realtively easy IMO. (But then..pulling a motor seems easy most days)

Ok well that scrapes that wet dream. Oh well. Is it possible to make a Gen 3 M90 fit a series I.

nope it will be nearly impossible to get the belts to line up. The casing of the m90 is 33% bigger so good luck bolting it to your lim as well.