2bbl covert to 4bbl

Hi my name is Michael, my english is not so good. I hope you can understand me.
I drive my 1970 Skylark 350 2bbl about 6 years.
Now I would like to convert the engine to 4bbl and want to install the following parts from TA / Performance

piston 8.5 or 10: 1?
Camshaft TA STG1
Rochester Quadrajet Level 1
Competition Headers
maybe even x-pipes

my question now, does a STAGE 1 intake manifold sense or a stock 4bbl?
Since I am a daily driver, I want a good fuel economy

thank you

 

They Stage1 intake will save you weight and would be a good intake for daily driving. I am not sure it would give you any better gas millage over a stock intake.

 

Ryan, thank you, what do you think about piston. 8.5 or 10:1 and x-pipes or not?
Michael

 

OK,
I need other parts, if I change from 9:1 to 10:1?

 

does it run good now? Smoke from tailpipe? Burning oil?
Are you planning to rebuild for the piston change? As you would need rings/rod bearings, cylinder hone or boreing.

If it runs ok and no problem with engine, a cam change with intake and a Quadrajet build by Quadrajet Power or Everyday Performance, buick specialists and here on this forum. A universal carb will not get the mpg or performance as the correct carb will.
A distributer recurve kit can improve mpg and performance also with a power time.
X pipe is good. Headers are not that important, more gains and reliability can be done on other parts like a torque converter or rear end gear upgrades.
Stock you probably only have 8.5 now, not the rated 9.0. And 10 to 1 cast pistons are about 9.2 actual compression. 70 had the option of using a steel shim head gasket that increase compression.25. Replacement gasket is thicker and would only be 8.2 compression on your factory piston

Get a 4 barrel accelorater cable to replace the 2 barrel accelorater cable

 

I planning to rebuild the engine and convert to 4bbl. I only know TA/Performance for buick engine parts because i am from Germany.
My choice would be

Camshaft TA STG1
Stage 1 intake manifold
pistons 10:1


Quadrajet from SMI Carburetor, TA doesn´t have a Quadrajet without core

Headers and X pipe, i am not sure

Is that a good choice, or is there something better?

 

Is this SMI going to get you a Buick 350 calibrated carb? That’s the question. I trust the carb builders mentioned as I have dealt with them and they do have Buick’s themselves. No , a Chevy carb is not going to be calibrated for a buick even though they are the same size engine. The x pipe system works fine. TA has 2.5 downpipes for stock exhaust. You are going to need a new timing gear set and valve springs. There was never a stage 1 350 engine so the stage 1 cam is more a big block cam. I don’t think your going to achieve much over the cam you currently have in your engine. Personally I would go crower level 3 cam or TA 212 over the stage 1 cam.

 

thank you , i will look at the homepage.

https://www.smicarburetor.com/products/sfID1/28/sfID2/9/sfID3/100/productID/840
i think its for buick

 

SMI is not my first choice, but the first i found a Quadrajet for Buick.
But now that I know that the other two are driving Buick, I will look for a Quadrajet there.

 

I wouldn't bother with the x-pipe system. It's not worth the hassle and $$$ for a minimal gain if any. Put that money elsewhere in the form of a converter or better engine parts.

 

Hi guys all good advice that quadrajet info. was inlighting as one would think 350 is 350 !? if someone can explain it clearer would be appreciated Ok the one thing i notice was no-one mention a HEI distributor As the regular points / condenser set-up at best is 15,000 volts !, & even the factory HEI is good for 40,000 volts !! after market 65,000 now you can open up your plug gap ! ok i too have a 70 skylark convertible 350 and just found a buick factory HEI in my junk and ordered a Pertronix tune-up kit so think about adding it ? also the x-pipe set-up may not add to much but it does quiet it a bit if you intend to run very aggressive mufflers ! the propose of the X is to help scavage / balance the exhaust out its rare to see / have an American car in your country Hope this info. helps

 

I have seen hei push 60,000 volts. But it’s not really necessary. A points conversion and a good recurve kit will provide more spark. Higher compression ussually wants less plug gap. But you will have to see what your engine setup likes most . I would open up oil passage to oil pickup tube and get a bigger pickup tube (76-80 Buick 350 Car). And get the booster plate.

 

For the most part the Buick point distributors are almost bullet proof. The HEI causes other problems with clearances, diff. plug wires needed, etc. I use & install the one wire electronic conversions ( the only one who knows it's been converted is you & I ) & re-curve the distributor for YOUR specs.

Tom T.

 

I already have the Pertronix II with the Flame Thrower II ignition coil.

What do you mean with "booster plate"?

 

Booster plate is a fresh surface for the oil pump gears. And it’s steel not aluminum, so it’s kinda like a girdle to slow aluminum expansion.

 

Hi Doc the pertronix would of been my second idea in 50 years of cars once i heard of this up grade been doing since always hated dwell readjusting especially on non GM cars ! even did it on a bone stock flat head ford what a world of difference ! on GM if theres a HEI for that group of engines in it goes ! as for all others watch out for the clearance between the reluctor ring & pick-up module as it needs to be 10,000 !! most of the time you need to shim between the gear & dist. body With either set-up you need the higher voltage wires plug gap is what the motor likes best I find whatever book calls on HEI i ran it 10.000 tighter I looked up 1970 compression your 2bbl is 9.0 & 4bbl is 10.25 with the high out-put & reg. 4bbl is 9.0 like the 2 This from an old Chillon's manual so if your compression is good all the other stuff will wake it up That oil booster plate is a good idea That buick only carb. still would like to know why buick is different that all the other GM 350's ?? Thanks

 

Hi not sure if its easy for you to explain for us why you need a buick carb over all the other 350's carbs ? I never heard of this till this tread As far as know there are just 2 Quadrajet CFMs 750 & 850 and the fuel inlet & choke set-ups are different i got hope i have one in my carb pile then lol well thanks if you can