I have a heavily modded 1999 Grand Prix GT but I just bought a 1988 Bonneville as well. I intend on buying the wife a Monte Carlo SS for her next vehicle so you can tell I'm a fan of the 3.8liter V6.

Anyway, just wanted to introduce myself over here. I will be having a lot of questions about the older series engine that I have on my hands because I would love to rebuild it over the winter. I will be wanting to give it a little more power so for starters, I want an Alldata account. I have two engine options;
V6-231 3.8L VIN 3 SFI
V6-231 3.8L VIN C SFI

I have my VIN number but I do not know where in the VIN, it wants me to look for a "3" or "C". My car is an SE.

Also, this might be a stupid quesiton but does this earlier Series motor have any aftermarket? When I do my rebuild, I want to put in a custom grind cam but I'm worried about air/fuel calibration and scanning.

Michael Peck

The eighth digit of the VIN tells you the motor, Hope for C, it'* got 15 more HP.

well you came to the right place

Wow, quick reply. Thank you very much. Yes, it is the "C."

I'm used to doing things radical to my Grand Prix. It'* N/A stock with only around 165hp but now it has L67 rods and pistons, P&P heads, headers, custom PCM, 42# injectors, cam, larger valves, intake insert, ported TB, intercooler, and a Novi2000. The tranny has a ton of mods too. For the 88 Bonnie, I want to do a lot of P&P work to the heads, lower intake, TB, and exhaust manifolds, then throw a 75 shot wet kit and see how she does. My guess is that I can get it into the high 13'*.

I'm sure many people will think I'm blowing smoke but this is what I did to my Grand Prix GT: http://www.cardomain.com/member_page...page_id=359756

Pector the GP looks pimp. kudos on the motr and tranny work

I'll be doing a custom grind for my Vin L engine, which is basically yours, with a nicer upper intake, and roller rockers. If I were you, i'd grab a set of 93/94 heads, and await my cam regrind.


I'm going to be doing a decent P&P to the stuff as well.

Thank you Jeep2Bonny. It'* been a lot of fun.

Jason, sounds like it'* right up my alley. I understand a lot about the series 2 motors but I'm blind on my 88 thus far. On my series 2, when I was n/a, I went to a cam that was .210 duration Intake and Exhaust. My lift was .317 on both sides and with 1.6 rockers, it put me at .507 with an LSA of 110. For heads, I changed my intake to 1.84" and exhaust 1.60". With that, I had to use an air/fuel calibration unit that changed the percentages on the MAFF sensor at 1k increments. Otherwise, I was going a bit lean with that setup.

Do you know the specs on our stock cam? Also, did you upgrade your valve springs?

I may do my valve springs, i'll have to find a set that works with ours, maybe the series II will. I'll be diggin into my donor motor some more this afternoon.

I have a spare set of L36 Series 2 heads in my garage that have 105'* from an LS1. The retainers are different as well. Once I pull my motor, I'm sure it won't take long to compare heads. I ordered a Chilton manual and an Alldata account. So far, I've not found many good specs from the Alldatadiy site. I can't even see what the intake and exhaust valve sizes are.

Holy F*ckin' HELL, Batman Sweet GP! LOVE the purge shot, that oughta scare the Sh*t outta some little ricer-boy!!!