nailhead matt

i have them in stock for 49 bucks. plug and play. also take note, you should run a 750cfm carb at bare minimum. difference between a 600cfm carb and an 800cfm is close to 50hp and similiar torque gain across entire power band. two biggest power robs on a nailhead are under carberation and narrow LSA. call me 9 to 5 to order 530 272 1564. i also have a blog with extensive 60 articles on it which ill be pulling when my book is finished later

yep you can put rubber rear seals in the early engines too about half the time. thanks for the shout out bill. yeah check out my blog. www.nailheadbuick.com/blog i have 50 articles on there now surrounding the nailhead, which i have written. articles consisting of parts identification. how to's. trouble shooting, and specs. buying parts from me comes with very extensive product support. i build 15 to 20 nailheads a year. its all i work on. all the parts i sell, are the same parts i use on in house builds... so i know what works and what doesnt, first hand. click on that link and scroll down 40 or so articles. i have 3 articles on rear main seal installs. one on rope, one on rubber, and one on the rope, in car, patch job. also information describing when each one is the best option.

its like me, giving my input on 455s because i specialize in nailheads. they're both buick right? that must mean all the same principles apply? hell no. thats how you look, spewing generic carb information, as if every engine thats a similar cubic inch, is the same. some times you have to know enough to know when you DONT know. buick also deliberately de-tuned their distributor curves as well. whats your point? does that mean its best (or perform its best) to leave it that way "because its stock?" of course not. the performancemodel (dual quad 425) got a better curve and over 800 cfm as a performance model, despite the same camshaft

100 bucks says youve never even had one of these engines before. but yet you think your generic, irrelevent information outweighs my expertise over something i actually specialize strictly in. its the definition of ignorance. this forum is the blind leading the blind. waste of my time

its extremely easy to swap a larger late edelbrock or afb on a nailhead. 57 to 63 dynaflow engines require a kick down adaptor that we sell for 35 dollars that take 15 minutes to install and adjust. theres many intake casting inconsistency variations, but most intakes require beveling of the edges for throttle plate clearance, or mod the top, remove the webbing, to connect the primary with secondary on each side, which adds probably 5hp by removing harsh 90 degree angles and increasing plentum volume. you WANT to block the heat riser passage at the top of the intake at the very least with 7/16 set screws. even better if you block off all heat at the intake gasket with special intake gaskets we sell. it eliminates related heat soak and vapor lock issues with the low boiling point of todays fuel. my 401 can sit in the garage for week and fire up on the first turn as the fuel hasnt evaporated out of the bowl. plus probably a 15hp gain with keeping the intake cooler. fuel will still vaporize just fine, contingent upon good attomization, as the intake will still get 135+ degrees.

to ACTUALLY take the thread to its intent, and rather than post meaningless shop manual documents, and clown on other peoples lack of punctuation. he asked whether to run a 650 avs2, or an 800 avs2. the 800 will give close to 50hp gain on a stock engine. that is a fact.

theres no nailhead that came from the factory with 10 to 1 compression without a very rare export kit for the earlier nailheads. all the 10.25 nailheads were only about 9.5. the compression ratios were only advertised. the highest compression stock nailhead, otherwise, was the 59 automatic 401, which was advertised as 10.5.... only ended up being 9.75, and i have factory documentation to prove it.

nah , he sounds like someone who got beat up a lot in high school

or we can talk about 455 buicks and what carb came on a 63 pontiac, as if that has any relevance to this thread, nor does it have any relevance to the point i made. i dont care. i just think its comical, when someone tells me that dyno results dont mean anything

comments like yours are typical of someone with nothing to offer the conversation. i shared information that i've learned from experience. information that i didn't have to share. i build these engines for people all over the world. including the IVO dragster clone. instead, the topic has gone off in a direction thats irrelevant to the post, making irrelevant comparisons, for the sake of trying to flex knowledge thats irrelevent to the point.

by the way. theres no 455 buick in 63. its not even the same engine family. you might as well be comparing a chevy

ive built over 200 of these engines and run them in my daily drivers and experimented with most the different intakes and different carbs. building strictly these engines is what i do for a living. so yeah, bigger IS better with these. its been prover again, and again, and again.. we also own quite a few factory experimental intakes. i get that you have a lot of carberator experience, and maybe im wrong about the carb sizes available at the time. regardless, youre turning the conversation into a direction that has nothing to do with this thread. the guy asked what carb to run. 800+ is the ticket as a fact. even on a 364

you got anything to add to the dyno results i provided?

there was no afb larger than the what they used during those years the nailhead was made. hence they jumped on the qjet, and the qjet performs significantly better. not because of the carb or the intake, but simply because it was bigger than the afb. not as good as the dual quad, however.

i realize this is an old thread... but... run an 800avs2 on it. really thats the smallest you would want on a 57 and later nailhead. anything smaller and you're leaving power on the table. you really wont notice worse gas mileage either... difference between a 600cfm carb and an 800s, even on a stock engine is close to 50 horsepower! its the single biggest, most affordable, performance gain you can do to a nailhead. at the time, buick was using the biggest carb they had available. stock afbs were only around 580 cfm. the 66 qjet was 715. thats why buick came out with the dual quad, which was probably around 800 cfm.