I will back up dbtk2. I believe he knows what he is typing about.
The 3.4" pulley was my first performance mod and it makes a huge difference. Well worth it.

Ok great. Now what size tensioner do I need to go with this? Or is the tensioner adjustable that'* currently in place?

You can leave the tensioner that is there in there if you want. You will then either have a belt that is a little long (but will still work) or you will have to buy a smaller belt. Probably 1/2" to 1" shorter than the one you currently have.

On our Bonneville, the transmission shift crisply using Castrol Syntec ATF Synthetic trans fluid (hard to find, but you should try it as I tried and verified it on several GM transmissions with all smiles, haven't noticed much on a Toyota trans though). It has certain friction modifiers that make GM automatics shift like it has a mild shift kit. Mobil Synthetic ATF and other brands don't make a difference in shift quality from my view.

As for robustness from abnormal combustion and transmission longevity with a 3.4" pulley:

a.) I've worked with boosted performance for years (had a '95 T/A stroker motor, MoTeC custom EFI, Vortech */C'd, featured in Hot Rod 4/99) and I'm pretty certain I heard severe but brief knock just after a shift as it'* tough to hear abnormal combustion that forces the PCM to pull timing 1-7 deg. but can definitely hear knock that forces 10+ deg. KR. I didn't hook up my AutoTap diagnostic to check since the incidence is rare but definitely a recent phenomena never seen <100k miles. Since I don't have the experience with L67 performance to the level of dbtk2 and he claims it should cause no problem with abnormal combustion, then by all means try it. But I would definitely get AutoTap or get a scanner and monitor KR every 15k miles or so as the vehicle ages and be prepared if you get notable & consistent KR to remap the PCM to maximize output. Generally in situations that for example you get KR of 6 degrees, you only need 1-2 deg. less spark advance to prevent KR of 6 degrees; "an ounce of prevention is equal to a ton of cure." This is because abnormal combustion w/o copious KR has a strong tendency to self-perptuate. OEM PCM calibration is conservative to account for production variability, variable fuel quality (or even an ignorant owner filling up with lower than recommended octane), motor age/deposit formation/injector spray pattern degradation, and extreme conditions (like lugging the engine at the threshold of trans kickdown climbing a mild grade towing a trailer all on a hot dry day, etc.) and any combo of the aformentioned. However going from ~7 psi to ~10-11psi (while remaining non-intercooled) plus a little age can take up all the safety margin and then some. So be vigilant.

b.) dbtk2 states the generous reserve capacity of the 4T65-E transmission. Again he has more experience than I do on this, but you have to mix that with the words of many other Grand Prix owners that the unmolested 4T65-E can run into problems even with moderate increases in hp; look up the torque capacity on this trans I bet you it'* 280 lb.ft. or right @ the stock engine torque peak as I read from somewhere. Although there are aftermarket beefed up units ($$$), GM has kept their engine output torque peak #'* at 280 lb.ft. (and 1/4 mi. performance) the same from the 1997 model right through this new '04 Grand Prix */C PARTIALLY for the reasons of transmission weak link story, despite rapidly improving competition like the Maxima and Accord V6. dbkt2 suggests a cost-effective shift improvement kit and I strongly suggest that as well since your Bonneville SSEi is heavier than Grand Prix GTPs. I think a 3.4" pulley, important shift improvement kit + labor, and possible PCM remap is overkill for getting into the 14s as aCiD stated but I do agree with dbtk2 that you'll be happy nonetheless. It will up highway roll-on prowess to stay on par with new Maximas, G35s, and ever faster fleet of new cars. Of course, if you're serious about making your Bonneville SSEi into a racer, then accelerating wear on your transmission shouldn't hold you up since fast racers aren't afraid of breaking things and spending $$$ :? Alas the perils of speed addiction

--- Like I said before, concentrate on getting your 60 foots down and you'll get into the 14s and enjoy a bulletproof stock car. I think you might even get there experimenting with tire pressures and launch techniques plus spring blocks or airbags will almost guarantee 14s with good air, good driving, proper tire inflation pressures. It'd be nice to see how fast you get it stock before moving on. And as I said before if you want more, then there'* no way out of a faster pulley ratio, minor trans mods, and some other supporting mods.

Best of luck!!! And keep us posted!!!

At 65,000 when we did all of the mods to the SSEi (unincluding the 3.4 which has been on since a few thousand) we also dropped the pan and changed fluid. This is the fluid we put in, because it is the fluid that we like and what we put in everything, we even have it in the GTP. Although I didn't notice any difference in how either transmission shifted harder afterwards, but this may be the case.

GM WAY underrates everything. Everybody that knows anything about GM knows that. When they rate the transmission max torque, they are very lienient. The transmission max torque is rated at 280ft.lbs., but that is also their little safety net window. It can really handle more like 350ft.lbs, and even more if you aren't abusive on the tranny. (I.E. going to the track every week) For instance, our GTP is making at least 420ft.lbs., probably more like 450, but since we don't drive the car like a racecar on the street, and rarely take it to the track, the stock transmission is holding up fine. BUT...GM underrates everything. Do you know what that means, that means the L67 torque rating is also underrated (to keep the transmission max rating happy). I have seen stock dyno numbers as high as 270 torque at the wheels on an L67. 270 torque at the wheels is ~330 torque at the crank, and that is BONE STOCK. Horsepower is about right on par though. And although GM has failed to increase torque rating since 1997, it is still higher than all the competition. If GM would just raise the stated torque to like 300-315 they would just kill the competition with their torque ratings, but if they did that it would be too much for the stock tranny, so they won't.

Yes, it is definately "overkill" as you say if you just want to run 1 14.99 to be happy. But this stuff will let the car easily and consistantly run mid-high 14'*, whereas stock you aren't going to see 14'* all the time, and it will definately make the car more fun to drive on the street.

Yup, I agree. Definately keep us posted!!!

Hey. Welcome to the club.
Reading that article back in 97 is what tweaked my interest in Bonne'*. It was an impressive article. I have been looking for it to read again but forgot the date...I have such a large collection of car mags...so thanks for posting it in your profile so now I can find it.

Found the article "The Bonneville Chronicles".
Great write up Eric.!

I had forgotten the key to your fantastic 60 foot times was the 24 psi front tire pressure and air bag in the rear to help with weight transfer.
I have been doing it all wrong with 35 psi in the front tires.

Have you done anything else to your SE since then? CAI and exhaust improvements like the article said you were craving?

I truly believe a 3.4" pulley would impress you a lot more than playing with sticky tires and pressures.

I definately believe so also.

Yup.

It sounds like this may be a good article. Is there any way somebody can post it online for me to view, or is it already online somewhere or something, I think I want to read it.

Only way I think I could do it is to scan it and send it to you via E-mail.
PM me your address and I could do it.

sign me up too, my e-mail address should be under my sig.