looking to build a 302

I have a 1968 350 block 2 bolt main

what crank do i need to install to get the combo right ? is it a 327 large journal or a ?

will stock 350 rod do ? can i use a stock 350 piston ?

any help will please

Thank you all

A 302 is a 350 or 327 block paired with the shorter stroke of the 283 crank. All you need is that block and a matching (large or small journal) 283 crank.

Originally posted by accontrol:
looking to build a 302

I have a 1968 350 block 2 bolt main

what crank do i need to install to get the combo right ? is it a 327 large journal or a ?

will stock 350 rod do ? can i use a stock 350 piston ?

any help will please

Thank you all -
The bore & stroke on a 302 is 4.0 x 3.0

The block will be a large journal if it's a 68

You need a 283 large journal crank & they are all cast which is not a big deal, especially in a 3" stroke. Lots of overlap which means it is a very stout piece.

A 350 rod will work, all small blocks are 5.7" except the 400 which is 5.565" & some newer stuff with like the 6.0 & LS1

The 350 piston will not work without a custom rod. Stock piston was 1.805 c/h

+++++++++EDIT+++++++++++++
My mistake, sorry for the misinformation, there is no large journal 283 crank graemlins/clonk.gif
Thanks M71 graemlins/thumbsup.gif
+++++++++++++++++++++++++++++++

can we use a 327 piston ?

the block is a 3932388 it just coud be a 327 ?

i look up the number they say 69 350 and 327 ?

i don't think there ever was a 283 large journal crank, they were all small journal, so a 283 crank is out of the question. you'll have to get a large journal 3" stroke crank, not a 283 crank.
no you can't use the 327 pistons unless you use the 327 large journal crank. you need pistons for a 302 if you are using 5.7 rods.

You could also use the later 265 (4.3V8) crank, these are in newer, I believe late 80s or early 90s cars. They are a 1pc rear main seal though, and you will need an adapter to use in you block. The good news is, the adapter is commonly available from GM.

Originally posted by m71:
i don't think there ever was a 283 large journal crank, they were all small journal, so a 283 crank is out of the question. you'll have to get a large journal 3" stroke crank, not a 283 crank.
no you can't use the 327 pistons unless you use the 327 large journal crank. you need pistons for a 302 if you are using 5.7 rods. =
You are correct, sorry for the misinformation graemlins/clonk.gif

Not supposed to be posting before at least two cups of coffee & brain is in gear :D
I was thinking 307/327 which obvoiusly will not work as it's 3.250.

Thanks for catching my mistake.

I have a 302 short block-but mine is a 283 bored to 4inches and 3inch crank-has 13-1 pistons-this is an inexpensive to build a 302! Wish you didn't live so far-I'd sell it to ya right! can you find a 283 block? some have thick bores that take the boring out real well! Good luck!

Another small journal option is a 327 block and a 283 crank (that is how chevy got the first 302 in 67). You will need a set of custom pistons. Of course there is always the chance that you could find a 302 crank out of a 68/69 z-28. It had a large journal to match your block. But they are hard to find and pricy.

the late model L99 v8 in 94-96 Caprices had the 3" stroke crank, but you'd need a one piece rear seal block to use it. but if you did have a newer block to use, you could also use the 5.94 rods out of that same engine with the 3" stroke crank and whatever 350 pistons you wanted to use. tha adapter someone already mentioned is to put an older 2 piece seal crank in a newer one piece seal block, not the other way around.
Chev also built a 262 in the 70's that was installed in Monzas, but i think the stroke on that was 3.1"- which might cause piston-to-head clearance issues.
i think you could get by with the old 262 monza crank, the 5.94 rods from the L99, and a set of 350 pistons with a little bit of custom machining (maybe offset grind it down to a 3" stroke or something?) and/or thick head gaskets. balancing might be a nightmare, but it could get built.

Oops, you're right, thanks for catching my mistake derrick.

this 388 is got to be a 350 block its got the long casting in the back for the distributor that go's all the way to the top of the intake

I was told that scat make a cast 3" inch large journal crank ..

What is the bore size of a 327 ?

did all the 302 have 11.5 compresion ?

did the angel plug head yield a 54cc chamber ?

for a 2 bolt main block they sure spind them hard

according to the grump they where flashing 8g all the time.. stock engine from GM ..

i wonder how that is posible...

302, 327, and 350 all have a 4" bore. The stroke is the difference. 3" for the 302, 3.25" for the 327, and 3.48" for the 350. That is the reason they all take different pistons if using the same rod lenght.

I've got a large journal crank out of a 75 or 76 262? that has a 3.1" stroke that would be very close to the needed 3.0 and will fit in a 350 block, or a 400 with spacers.

What do you mean by 388? Is it currently a stroker motor, 388ci? Or are those the last three numbers on the block?

because a 388 casting is either 350 or 327 when it only has 2 bolt mains, all the 4 bolts were originally 350's.

The Grunp was right, the only way to make a 302 run is to wind the snot out of it.

yes the last 3 digit are 388

did any 350 have the casting for the distributor
hole go up to the top ?

I was checking the archives on building a 302 out of a 283. My husband says you can either use a small journal 327 block and the 283 crank with the 302 pistions, or a large journal 327, or 350 block and 283 crank, but you have to use the thicker clevitte 77 bearings. Can anyone conferm this? Sometimes I think he likes to blow smoke at me. He actually thinks I can't build my own car.

There are bearings available for putting the medium journal size (350) in a 400 block but I've never seen them availble for the small journal crank in a 350 style block. You could have the main journals welded and reground for fit in a 350 block but I bet that wouldn't be very cost effective.

I think I'd have a better chance of talking him out of that 350 he has comming, than trying to build a 302. I just wanted to beat his 240Z hybrid with his 5.0 ford with a chevy 302. I've been informed in another topic that the weight of my car will kill me.

What you need is more torque, instead of building a smaller motor, what you need is a larger motor. However, if you want something to wind up like a 302, try making a 348 using a 400 block and a large journal 327 crank.

I have a 67' 283 block. Can I build a 302 out of it?

Yes!! Just bore it an 1/8" over and you have one...

I did just the opposite b/c I used a worn out early stock bore, 327 block and an old '55, 265 crank and junk 283 rods to build my junk 301 motor...

Bought a $34.95 set of W/JCW 1/8th over, 283 half round, 1/8th inch domed, el-cheapo cast pistons to boot....

Coffee-cannned the solid lifters that went with an old -097, little Duntov solid cam and Z- springs and I used to wind her up above 7,000rpm all the time.. And the sucker wasn't balanced at all.........

To this day, I love the way she would rpm once rolling....

pdq67