hey fella's. my old 81 has finally insisted for an overhaul and i'm looking for some new pistons. i got to looking around on ebay to see what there was and to maybe save a little coin, but my question is, i see pistons for auction that are specified for use in 60's or 70's or for 80's style engines but isn't a 300 still a 300? were there different bore's throughout the decades, so is it something else like pin diameter for example?

also, while i've got some of you here, i'm planning on making this engine a little beefier... wanna do some pulling w/ it, u kno, stock trailer...camper...torque for pulling, u guys get the idea? so far i've got a 4 bbl intake and long tube headers bought and decided on a comp 260h cam w/ new lifters, springs, and maybe rockers if necessary. haven't secured one yet, but also have a 240 head on the list to increase CR. in addition to a 600 cfm carb and warmer ignition system the only thing i think i'm missing is where i want my CR for sure... if i go .030 over and want do generate more torque, am i going to want to keep the OEM style piston or is there a possible flat top option?

Thanks in advance for any and all information!!!!

 

300 used the same bore over all years. Somewhere around late 70 or early 80 the pin diameter did change, you might find the specific year on a search.

.9122" early
.9752" later

Id imagine a comp 252 would give you more ***** down low if your just after pure low end.

500cfm carb would likely work fine.

There is no real advantage to having the 240 head, so if you dont have it, dont get it. You can use 351w pistons, just make sure you have the right pin diamter(rod). If you do a search, some folks use 390 pistons, just keep in mind, the stock 390 bore is 4.040 I believe, so youd need to overbore the 300 to .040. (Id just look into the 351w pistons) The old six banger seems to respond well to a higher compression ratio. You and your machinist will have to measure your cylinder heads combustion chamber, do some measuring on the block and see which pistons to get.

 

if you are going to sup it up at all i recomend eather hypereutecic or forged pistons becouse the stock aftermarket cast pistons have weak skerts and if they brake your block is runed.
if you use 351 pistons you will need to use early rods with the small pin or rebush your rods to fit properly
some people use 352FE pistons i forget the bore but i think it is the same as 300 (4.000), 360-390 pistons use 4.050 bore witch leaves your cylinder walls a little thin so if you dont half to i wouln't
the 352 pistons use the late modle pin diamiter, also to get a decent CR youl half to mill .050 off the top, and you should first measure the deck hith that should give you about 11:1 CR with carb head 12:1 with EFI & 240 heads
i also had a thought that maby if you used 300 crank, 240 rods, 240 forged pistons and milled the tops down that might give you the same efrct as the 352 pistons.
annyways good luck and have fun
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only thing beater than a diesel is a 300-6

 

Uhh...:
Two things...11:1 and 12:1? He's going to have to mix his own gas.

Your tag line "only thing beater than a diesel is a 300"--Are you trying to say "...only thing BETTER...."??? Or are you making a reference to some people who own 300s (wife BEATER) or the condition of vehicles with 300s (old BEATER)???

 

yes i know he would half to run race gass to run that kind of compression, but with those options maby he can find a setup with 10:1 that should run on 92 octain and thak you i ment better not beater i ges i missed that spelling errer, i have had 5 ford picups, three of witch i converted from 302 to 300, the rest allready had them 8)