hi I recently purchased a 69 340 short block. Has been bored 40 over and everything looks good. Has been ran before but I just took a rag and wiped off the piston tops and they are new. Motor didn't come with heads just a short block not even oil pan. I just purchased a set of 1970 U heads. My questions are should I do anything to these heads as far as port work or milling? Also what cam and intake would be good with this combo. I don't want a race car just a street cruiser with good power but still drivable. Its going in a 72 duster auto.
Are these U heads in good shape, reconditioned, new (not likely)? The stock heads, without milling or porting worked very well on stock 340 engines. The necessity of milling is determined by head surface condition and the desired compression ratio. The compression ratio will be determined by the fuel you choose to use, the piston deck height, the ignition timing and the camshaft intake timing. Are the pistons flat top? Do they have valve relief notches?As one who ports heads and builds engines for a living, porting will increase the performance if done by someone who knows what they are doing, but is not likely an expense necessary for street performance. However, we have ported the heads on EVERYTHING we have ever built, stock or race, to one extent or another.There are perhaps 30 different cams and 12 intakes that would work well with a project like this. Everyone who reads your post will most likely have a different favorite. Do you have any used intakes, stock or aftermarket, in good condition, available to you?What kind of budget are you working with?
First off the pistons that are in the engine a flat tops with no valve reliefs. I have a 318 in the car right now that has a stock 4 barrel intake but i would like to put on an aluminum one. I would like to run pump gas. I already have a drag car that i run race fuel in that i built but thats a chevy. My budget isn't real huge but if im gonna build it im going to do it right.
Still not enough information for an accurate selection of camshaft. What are the head cc's and what deck height do you have with the pistons? Gear ratio? Tire size? Torque converter stall speed?
I cleaned the pistons up and found that they are the TRW 2316 .040 oversize forged 10.5 :1 factory type replacement pistons. As far as gears im currently looking for a rear end now. Probably gonna be a 3:23 or a little more depending on what I can find. The engine had a cam in it I just pulled it and its a comp cams 268H. I think that it would be ok for what I am looking for. I might go to a 2-2200 stall. Thanks
A 2000 stall converter? That is less than stock. 340 auto's had 2400 stall, not that 200rpm of stall will make much of a difference. Sounds like you have a nice street motor.
Oh I didn't know that I currently have a 318 with a 904. Im going to install a 727 in it with the 340. Maybe a 3000 stall would be more suited for the job. Also what intake and carb combo would you recommend. I have a good 700 double pumper holley I was thinking about using. thanks
Now your talking, a nice Hughes 3000RPM stall converter will do wonders especially with the Holley 700 DP. Be sure to install 50cc accelerator pumps front and back on the carb. You will also want to install some 35 thousands shooters front and back. I recommend increasing the rear jet size by one number as well. Intake? RPM airgap with a 1" 4 hole spacer. Hang on cause this set up will really wake up the motor. Nice set of headers would only add to the horse power..