Thread: 302 build

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Well I am going to put a 283 crank in my 350 and build a 302, i have a crank out of a 1962 or 1963 283, a 350 out of a 76 pickup and 60cc heads from a 1964 327. I know the crank journals sizes are diffrent and but i cant seem to find the spacers to go from a 2.45" main to a 2.30"??? Also I'm pretty sure i cant use the pistons or rods out of the 350 right??? basically I just need to know what all i need to change to make this work and possibly where i can get them

you can also track down a large journal 302 chevy crank. or you can ahve a 327 if you use a 307/327 crank in your 350 block. i run a 283 bored .125 over i like these little motors alot but have never done it the way you are trying. i would try to find a 302 chevy crank. you can get aftermarket ones now for about 500ish i belive not a bad deal. whats the casting numbers on those heads?????

couple of quesitons

whats the main purpose of this motor? race track? street?
what kind of car is it going to be put into?
what kind of heads, cam, and intake did you have in mind?
what do you want out of this motor?

Well one second here if you have a 283 bored .125 over you would have a 4" bore right? because the stock bore is 3.875, so you would have a 302? Well I have the 283 block and it would be a lot easier to just bore mine out, but can i bore mine out that far??? The casting # is 3834812....283...1962-63...2 bolt main the ID # is FO72IDK

yes a 283 .125 over makes a 301.6 <302> and you will need 302 pistons. make sure you have it magged 1st then have it bored if it checks out ok. i have done a few of these motors up and have learned from others who built them alot in the 60's and 70's but make sure it checks out ok on the wall thickness. and dont let nnybody fool you, if done right it wont overheat. i have a 160* stat in my car it goes to 160 and stays im actually having to change to a 180* because it wont warm up! also the 2 bolt main will be just fine.. whats are you going to use this motor for? strictly racing? street driving? what kind of car are you going to put it in?

Awesome that will save me some $ and what year 302 pistons will work and do you know where i can order them from? and i just use the same 283 pushrods right? sry for all the questions but i've never messed with a 283 before and its just going to be my toy to kill fords and kill ricers with on the street and its either going in a 1979 camaro or if i can get a front drive distributor a 1994 camaro

those are both pretty heavy for this motor, i would suggest we build some torque into this motor. i would suggest a 6 inch rod any year 302 pistons will work. they are full floaters when the times comes to get rods make sure you get "bushed" rods for full floating pistons. getting a new set of pushrods would be a good idea that are pretty cheap insurance. you can get new pistons from SRP and JE i believe i have trw's you can find those on ebay every now and then. let me go voer my notes and i will post tomorrow

Back in the 60's , we build a circle track engine using a 327 truck block with a .125
overbore and a 283 small jurnal crank . This gave us 321 cubes , they had a cubes to
weight rule , this saved 100 lbs total car weight . The first block we bored hit water
the truck block may have been a thicker casting or we got lucky.

Originally Posted by gassersrule_196

those are both pretty heavy for this motor, i would suggest we build some torque into this motor. i would suggest a 6 inch rod any year 302 pistons will work. they are full floaters when the times comes to get rods make sure you get "bushed" rods for full floating pistons. getting a new set of pushrods would be a good idea that are pretty cheap insurance. you can get new pistons from SRP and JE i believe i have trw's you can find those on ebay every now and then. let me go voer my notes and i will post tomorrow

Heck boy give it some real umph, Eagle makes a economical stock appearing rod
in 6.250 of course ya gotta use custom pistons but the rods,pistons & rings will only set ya back 12 to 15 hundred. Thats what we did on the 305 (actually 318)
sprint car motor and that things a horse.........

howcome everyone wants to go .125 over on there 283's? so you have a 302, thats pretty cool but your not making loads of torque, although you rev good. if you like rpm's why not take that 283 with its super thick cylinder walls and run a bunch of boost or nitrous through it with some top of the line rotating assembly, splayed 4 bolt caps and some wicked heads?

The problem with a Full on Boost/Nitrous 283 or 327 S/J Build is . No one make's 4-Bolt Caps For them and if they Did the Blocks are not thick enough to install them . As you Said install a Top Line Rotating Assemble . Yes that can and Needs to be Done . Because the Stock Rods are not very strong with there 11/32" Rod Bolts . You can Buy some Pro Rods with Cap Screws . And Stud the Main Caps this will make the short Block Stronger . But If some one had there Mind Set on Building a Stronger 283 . Take a 307 Block and install an L/G 3.000" Crank . Now on this Block you can add the Splayed Main Caps . And Use the Stronger L/J 5.7 Forged Rods . Then you would have a Stronger 283 to rage on .

So what is the difference between a 4" 350 piston and a 4" 302 piston?

Originally Posted by smokinz28lt1

So what is the difference between a 4" 350 piston and a 4" 302 piston?

Pin Height .

Well, I have to ask.... Why do you want to go to fewer cubes???? Mini mouse motors were ok in there day, and then only in light weight cars.... A good street motor needs to make torque at low rpm, not horsepower at 8500. The novelty of having a mini motor wears off quickly when the valve train and other internals continually fail because of the extremely high revs you have to twist the engine to make any power.
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Why not go the other way, build your 350 into a 383??? Get the correct cam and head combination to build low rpm torque....

I do Like that DZ-302 Lot's of Nice Factory Forged Parts . But I always thought the 1970 LT-1 350 370 h.p was the Better of the Two SB Chevy's .

I agree with the cubic-inch guys. I had a 283 back in the '60's, .060 over bore, Duntov cam, 327 heads, etc. A real revver, but nothing on the bottom end. It was fun to drive if you revved it to 7500 in every gear, but I wore it right out in one summer! There wasn't a good piece in it after less than 10K miles. Pistons, crank, cam, heads, all were shot. 'Course, that 10K was pretty much quarter mile bursts, but a 350 would have went better and lasted much longer (though not at those RPM's!).