305 pistons in a 265 chevy v8

so im looking for some 265 pistons that arent brand new for big money, and ive found a few but, im wondering if an oversized 305 piston would fit in it? the stock 265 is 3.750, and i see 305 pistons that are 3.766, 3.756, ect. the only thing that i think would be an issue would be the pin height? anyone have any experience?

 

do they make flat top 305 pistons? i think most of them are dished....could be wrong

 

and according to summit a 64 and 65 pontiac 6 takes the same piston?!? http://www.summitracing.com/parts/slp-w233p/applications/?prefilter=1

heres one thats an oversize 305 no valve reliefs but its dished in


stock Comp. compression height is 1.780 and Pin Diameter is .9273 Offset im thinking this should work? maybe with a slight loss in compression?

 

The stroke is dramatically different so pin position won't work.

 

Yeah, a 305" piston will fit in the hole, it just won't have any compression.
FWIW, your 265" has a 3.0" stroke and the 305" has a 3.48" stroke. Pin height will thus put the piston .240" down in the hole.

jack vines

 

It was considered but forgotten because of the dish top and the pin height, although a guy could find a long rod , Rover . It just doesn't add up , Egge has the proper piston.

 

if the pin is nearly the same distance to the top of the piston it doesnt matter how long the rod is?

 

Bore it out to a 283 - better yet, bore it to 283, get a small journal 327 crank and use 307 pistons!

 

im reading conflicting things on if it can be bored that far. that would be cool tho cuz i got some 283 pistons and rods someplace.

 

Is there some particular reason it has to be a 265"? Later, larger SBC cores are going for s**** price, machining costs are all the same and rebuild kit for a 350" costs less and they can be made to look the same externally, if it's a consideration.

jack vines

 

because the 265 has no side mounts and im running front mounts, because it has staggard valve covers, because it was made in 1956 not 1987 or whatever, and most of all.. because i have it sitting in the 46 dodge truck right now(without its guts in it)! lol

 

Yes - I've done it - I built a "small journal" 307 using a '55 265 block and early 327 crank and rods - the 327 rods have a little more meat on the big end, but not necessary as the 283 or even 265 rods would work fine - we did have to grind the block for clearance of the counterweights and rods - I don't know if a '56 block has more clearance or not - if you've got some stock bore 283 pistons, I'd go that route - if you have the 283 crank you could avoid having to ballance the ***y - the 265 crank, while being the correct stroke, was set up for lighter pistons.

 

YESSSSSSSSSSSSSSSSSSSSS!!!!!!!!! thank you! saved me a lot of money buying parts that might not have fit.

 

Bondo, you are talking about the early 265, not the late 265.....then....
http://www.ebay.com/itm/Chevy-265-V...ies&hash=item2c5c237d49&vxp=mtr#ht_1698wt_811

 

There are plenty of the early 265 pistons on that auction site we all know and love. There are even pistons for the late model, baby LT1 265, but those won't work for your application. There is even a NOS set of high compression, 265 pistons up for auction. My plan was to use a Canadian, 4 bolt, 305 block I had located, a large journal 302, 3" stroke crank, and some after market 265 pistons I bought. Just bore the standard bore 305 block .014 over to standard 265 bore, and we have a very strong bottom end "265". But, my plan fell all apart when the block was bad, my crank was stolen, and the pistons turned out to be "semi-finished (virtually no one does piston grinding any more). So, I'm building a 283 short block, but using the 225 HP, 265 heads and intake/carbs. And, the H.O., 305 pistons are flat top, with 4 valve reliefs. Butch/56sedandelivery.

 

I'm building a 1956 sbc 265.
I'm using 305 pistons with 6" rods.
That's give me 9,04 vs 9,025 deck height.
Almost perfect. Easy to adjust.
Detail: I live in Brazil. Here we can easily find 6" long chevrolet oem connecting rods with small journals of opala, omega, silverado, etc.
So that's truly possible and cheaper than buying the correct pistons for 5,7" rods

 

^^^^Those small journal , 6 inch connecting rods would be of interest to a lot of us here in the States. Tell us more!^^^^ Use the flat top, with four valve reliefs (or aftermarket, race, 2 valve relief, pistons), and not the dished pistons. I have a NOS set of .030 over, Ohio brand, 305 pistons, that are flat top with four valve reliefs, that I've tried to sell CHEAP, and no one bites.
I am Butch/56sedandelivery.

 

Been looking at Eagle SIR 5140 Forged S.J. 6" rods for my long rod 302 build, also interested if cheaper, cause that's me
part #EAGSiR6000SBLW 6.000 Bushed, 3/8 ARP 8740 (615g)
Compe***ion Products in Oshkosh WI. $297.95 a set, free shipping Nation wide over $99

 

I could bite. lol

 

The only downside of these rods: they are for 6 cylinder application, so you need to grind one side so 2 of them can share a journal in a v8 crankshaft. But no big deal. Everything else the same. As you can see the pictures. The v8 and the 6cyl.

 

What size GM 6 cylinder ? We have Silverado pickup trucks here , may have same GM engines in the states. It don't look like a rod that you use in high horsepower application

 

Does a set of rods cost less than a set of pistons? You can get a set of pistons new for less than 200 dollars. I am a cheap ******* myself and everyone knows that but that is probably in my price range.

 

Or cut down the 305 crank main journals and build a 305 that doesn’t have side mounts

 

The General Motors of Brazil had a lot of peculiarities, differences. The 6 cylinders here stayed small journal measurements. And some with 5.7 and other 6 long rods.

 

The quest I did was because I do not live in America. I live in Brazil. 1 dollar is 5.5 reais (local currency). Amd we have a lot of customs taxes of importation. So to me is faster and cheaper go this route.
In the USA I do not see much advantage to go this way. You are right.

 

By the way.
If some of you could spare some knowledge:
What can you tell about the original rear oil galley plugs of the 265 engine. The plugs heads are plain flat and don't seem to be threaded. Each looks like a solid cilinder pressed. Are they pressed like the front ones? Thanks

 

Yep!.... There's also one on the driver's side deck near the rear "China wall".... That one should be threaded with a set screw....

 

I am not acquainted with your import taxes. We get around them or have in the past in some European countries by sending a gift, no taxes on a gift in some European countries. If that would work in Brazil you could have a novo tio. There must be some reason for your uncle to send you a gift. Compreendo?

 

Considering the difference in the cost to build a 265 compared to a cheap 350, I'd get my grinder out and grind the side mounts off the casting if they really bugged me that much.

 

LoL.
Compreendo.
import taxes = 60% of the total value (product + shipping)
That strategy of "gift" doesn't work anymore here...