Fred, After much talk with BDS...I have a 454 I have installed an 8-71 blower on. The owner of BDS told me, if I was going the carb route, to use the Holley 750 double pumper(4779). He said the Holley was by far a better platform to tune for my 8-71 blower. I bought two...had them dyno-tuned by BDS, and the results have been fantastic. The BDS owner doesn't seem to like BG Carbs.
I also have a friend that has a 72 GTO. They put a 750 Demon carb on it and it's run poorly. They just switched it to a Holley and the engine is running much better!! I like the design of the BG carbs...and was serious on getting a pair for my blower.....Now....I'm glad I went with Holley! I wonder if anyone has had good luck with BG's? Dan Mascheck Wharton, TX -----Original Message----- From: Fred Dowaliby [mailto:[EMAIL PROTECTED] Sent: Saturday, June 25, 2005 8:34 AM To: The Chevelle Mailing List Subject: [Chevelle-list] 454 carbs Hi Folks, I am once again in need of your expertise and advice, this time re: carburetor selection and tuning. My car is a '68 Chevelle based 32 Ford street rod, 454/th400 with 3:08 rear. I estimate it weighs about 2800 lbs. Pertinent engine vitals: flat top pistons, Edelbrock Performer RPM heads, air gap intake, Comp Cams CB 280H-10 cam. The stall converter is 2200. I am currently using a new out of the box Holley 750 dbl pumper carb. I have tried a Speed Demon 750 vacum secondary. Both have resulted in lackluster performance. There is no bog, they just don't have any punch. My comparison is the carb I was using (never should have sold it!), an older Holley 750 dbl pumper. That thing used to run like a beast! I replaced it with the Demon because it just looked grungy, I got sucked into how pretty the demons looked, and I wanted to "clean up" the engine. I then replaced the Demon with the Holley thinking I should have stuck with mechanical secondaries like worked well before. This resulted in the same lackluster performance. I made the mistake of breaking the rule "If it ain't broke don't fix it!". I am at a point where I just don't know what to do. Is a 750 big enough for this engine? Should I start playing with the main jets? I don't know what's in there now, but I recall the old one had #72/#70 for primary/secondary. I don't have any experience with carb innards. Should I look for a trustworthy carb expert/shop? Thanks for your help, Fred Dowaliby
