I’m new to this website and I recently purchased a 1971 Buick Skylark with a Buick 350 engine. I’ve just got done with a lot of the upgrades like full suspension, brakes and other things to make it more drivable because I actually want to use this as a daily driver. It has the TH400 and shifts really smooth. It’ll definitely need a new positraction because the guy who owned it before broke it drag racing. The engine already has a couple upgrades like the TA performance intake manifold, aluminum headers and dual exhaust although I don’t really know the brand. It runs really good for a 50 year old car. I’ve driven it for 2+ hour trips twice now and have had no problems but now I’m looking to get into the fun part of making it faster. I know that the cam isn’t stock and I could tell you what it is but assuming that I’m going to replace that too what parts should I get to make sure it’s reliable first and foremost, but also fun as hell? My budget right now is about 6500
Others may disagree w/me here, but before getting into the engine since it runs seemingly pretty well & since you need a rear, I think I'd ditch the TH 400 for a 200-4R (.67 overdrive) and install a 4.33 or 4.56 rear. You'd still have $ leftover to start planning an engine build or engine mods & w/those gears while it may run out of steam in a full ¼ mile run, the car would be a lot quicker on the street or even @ an ⅛ mile track.
Why only 4.10? That would give a final drive of 2.75. Even 4.33 (2.90) or 4.56 (3.05) would be great on the highway even @ 85MPH and seemingly even quicker off the stoplight.
I agree on the rear end upgrade since you said its worn out. Also on the trans swap to a 2004R. Personally Im not a fan of the Turbo 400 behind the 350, the T-400 first gear is a tad less (2.48 versus 2.52) and the T-400 absorbs more power. With the T-400 behind the big blocks, the taller first gear and more power to operate the T-400 arent issues.
Do you guys have any recommendations on what website to get the positractions and what I should be looking for exactly? I really don’t know what I’m looking at when purchasing
Welcome! http://extremeautomatics.com/index.php?category=17&searchtext= and for the rear Monzaz on this board
Talk to @BrianTrick or @monzaz on here. The stock '71-2 8.5 rear is a good starting point and either can advise you on the carrier/gears, etc. & should be able to build you a rear for a pretty reasonable price.
Yw! Going to be taking my '70 3.64 up to Brian next mo. Will check out the link you posted on the 200-4R's. Once I get my basket case '71 GS convertible together (probably be m/l stock drivetrain to begin w/), I'm intrigued by going w/ the 200-4R/4.56 setup and an aluminum head 350.
After I get those straightened out though what are the first engine upgrades I should make to get the most reliability and power out of it? I was thinking the TA performance cylinder heads, rocker arms, maybe a new oil pump or something? I’m pretty new to this and I have a fairly decent amount of money to spend on it right now but I’d definitely like to get the most bang for my buck
This might be a stupid question but is there anyway that I could figure that out easily? I know there’s been a good bit of things done to it but I don’t know to what extent
410 yes... you turn 2200rpm WITH the convertor locked up going about 65-70 AND a 373 gear and 28" 275-60-15 tires. that is 2400 rpm with no lock up and 373 gear and 28" tires 410 is plenty for a street car and a 200 4r trans You don't want to spin the motor faster than that on the highway. 2500 tops.. then the engine starts singing after that. You also have a lower 1st gear with the 200 trans don't need no more rear gear unless you plan on racing in a bracket class then I would do the 430 gear +
It is stock there is no other unless new **** was put in in the last 4-5 years 73 capscrew rods are what is there if it was upgraded at all before 5 years ago
Plenty with 410. I went from 308 to 390 to 410. Unless you are building a track only car, or spinning to 7,5k, 410 is the best gear ratio with a 2004r. Do the 456 and you will see.
Hard to really know 100% without pulling the oil pan and looking, and maybe removing a main cap/rod cap to check bearing size? But you can look for the block casting number on the head surface without taking anything off, might just need some cleaning. That will tell you what the engine originally came with, but of course it may have been changed by someone. You're looking for a 2 letter code like "SP". There's another thread that details where it is stamped, but IRC it's in between the #1 and #3 spark plugs on the deck. Sometimes these stamps have been erased by head milling though. You can also stick a borescope down one of the spark plug holes to see if the pistons are stamped with anything, often they have a "0.030" or some such stamp on the top, indicating a non-oem size (and therefore re-bore). With the borescope you can at least confirm that they are a stock style piston (look for nipple in the middle). EDIT: Check post #6 in this thread for pictures: https://www.v8buick.com/index.php?threads/need-help-iding-the-year-of-a-455-block.58144/
Maybe so. I've never done the math for trap RPM but certainly would before making that decision. I assume it would matter whether one is building a car for ¼, ⅛, or street (stoplight), peak HP @ what RPM, etc.
and the decision is... if the math was not done how can an assessment be made here then. now give the specs for 1/8-1/4- street etc.
So a compression test on motor and or a leakdown test need a air compressor to assess. The bottom end will not be nothing special more than likely stock. If you plan on using alum heads I woould take the motor out and have the oil mods done first and that is the most important part above anything else that is done. Get the shortblock rebuilt and bump comp and go from there 9.5-10 comp on street will be enough If you want more and you can with alum heads then go to 10.5 comp this will keep you safe on the gas. Maybe 11.0 with alums should be ok but 10.5 is good also.
