AS&M all the way. from what i've heard ppl just have problems with everything else.

 

i have had both bbk 52mm and now a holley 58mm and can vouch both of these perform very well...its basically your preference on looks and price...most all of them do there purpose the same...

 

Arizona Speed & Marine is without a doubt the best one made for our cars.

 

Ok, having owned just about all of these talked about as well as another one that hasn't been mentioned, here is my 'overview' of the available units:

AS&M - Beautiful fully polished billet piece, spring is slightly stiffer than the BBK and others, biggest issue is the top-plate uses a AS&M only bolt pattern so that is a consideration for custom top-plates. I believe it is also are the only throttlebody out there that comes with it's own polished bottom IAC/coolant plate from AS&M...

BBK - Cast unit with minimal machining. Early units had an issue with IAC bypass port sizes not being right, thus people having to drill them. Earlier units also had a lack of finish machining in a poorly cast IAC area that caused a lot of whistling depending on the motor it was installed on, thus further work was needed to lessen the noise if you owned one of these units. I beleive they 'fixed' most of these issues over the years and they are truely a bolt-on and go type of setup...

Holley - Another beautifully satin billet unit. PVC fresh air and CCP inlet tubes are directly perpendicular to the throttlebody itself, thus those hoses seem to 'stick out more' as they aren't angled like the stock setup or the others here. Not much of an issue, but still noticeable if you are highly '****'...

LPE - Beautiful brushed finish billet throttlebody. It is machined out of chunk of billet and in more rectangular looking than the stock 'throttlebody' design of the others listed here. It uses a seperate 'air horn' plate for connection to the intake elbow, thus it uses 2 gaskets instead of 1 like the others. It has a standard bolt-pattern for the top-plate, but has the bottom two edges of the top-plate are rounded, which is another consideration for custom top-plates. It uses a TPI-style TPS sensor vs the stock TPS the other throttlebodies listed use. This one also sits almost a full inch further towards the front of the car compared to any of the others, or even the stock one. The spring used on it has a lighter 'feel' to it compared to the others listed as well, which gives a subjective 'feeling' of easier/quicker response...

Now all the above units work great. They all do what a throttlebody should. A few points to remember: ALL aftermarket throttlebodies require you to adjust the TPS sensor once it is installed... Some get closer to 'ideal' than others, but in most cases you will have to slot the TPS sensor holes if it re-uses the stock TPS sensor. For units that don't reuse the stock TPS they already have adjustability built in to the sensor provided. ALL throttlebodies except for the AS&M require you to transfer your bottom IAC/coolant plate over to the new throttlebody. SOME units (such as the Holley/BBK) may require you to enlarge the IAC bypass hole on the unit to reduce split BLMs in big cam stroker motors. ALL units except for the LPE pretty much match the dimensions of the stock throttlebody, as only the LPE requires you to plan for the further distance from the intake itself for intake elbow hookup (really only a big issue on Vortech Aftercooled setups like mine where I had to modify the intake piping to get it all properly lined up with the LPE unit installed)...

Now the big key here is, they all work just as well once installed... So it comes down to what do you want looks-wise... For my 'opinion', the AS&M/Holley are almost identical in looks, with the AS&M being polished aluminum and the holley being more of a satin bright finished look to it. Having both units sit side-by-side, the AS&M shines more. The BBK is your 'low-end' product as it is rough-raw cast, but would be ideal if you plan to powdercoat the throttlebody to match the intake manifold. The LPE is the most 'different' being a giant chunk of brushed-satin finished aluminum, it also had a different TPS sensor and in general is massive looking, but with the most 'issues' in regards to fitting into various setups...

I have owned each and every one of the above listed throttlebodies, and I am on my second LPE unit because it is so 'different' looking. I pretty much went with a brushed aluminum and black theme on my engine baythis time around, thus it fits right in... On another car I owned I put the Holley and it was a jewel with a blue intake manifold and blue headers... The BBK was functional but not really 'nice enough' for me as I wanted my engine compartment to look as nice as the engine itself performed... And the AS&M was gorgeous with the only reason I got rid of it is that at that time I needed the cash more than I needed a very expensive bling piece, besides the motor was out of the car and being rebuilt...

If pictures are desired, I might be able to find some pics of the Holley in my archives, and I know I have pics of the LPE unit online...

I hope this helps...

Dennis

 

I got my BBK 58mm throttle body about 6 months ago. In my mind, it is a piece of crap. Looks are not great as it is a casting with very little machining. Finish was poor. The surfaces were not deburred after machining. I had to stone the mating surface to remove the flashing from when it was machined. The throttle bodies were also not machined on center in the casting. The machining was off center side to side by about an eighth of an inch, looks horrible when you look at the blades. I don't know if this will affect performance, but it surely does not help it. Lastly, the functionality was problematic from day one. I had to open up the mounting holes for my TPS to get it to idle below 2000 rpm's. After about a week of it being on the car, my car began to idle very inconsistently. I suspected the TPS as it was the original, and it was a cheap part, so I replaced it. Same problem. What I ended up finding after hooking up the TechII to my car, was that it was sitting stationary at anything but 0% throttle position. This caused me to be idling at about 2800-3000 rpm's. Not cool when you have a restricted license, and you are brake torquing a smoke cloud at a traffic light, and it is not intentional. What I found was that the joint between the throttle blades (the center shaft) and the cable track where the throttle cable pulls the blades at had come loose. It was a press fit, no dowels, no bolts, a cheezy roughly 3/8 rivit holding the two halves together at the pivot point. I welded the seam back together, and finally, haven't had any problems since then. The only other aftermarket TB that I have seen on an LT1 was the Holley unit, which looked and fuctioned much better, for the same price. My vote is avoid BBK!