"Yes"   Every motor will benefit from a flow increase or as i like to say a "less restricted port design" now this does not mean go out and buy the largest set of heads that will fit on your motor. port size or volume and air speed are very important.while a set of 44x37.5 may work on a 1600 motor,it's not needed.(unless it needs to work at 8,000rpm) I had a customer that wanted to spice up a 1200cc motor.so i increased the intake to 35mm valve and back cut the valve to help out on the slow air speed of a 1200,removed the intake and exhaust guides from the ports,worked on unshrouding the intake valve,inside the chamber(due to the low lift of the cam),opened the port to the stock gasket and added hi rev springs. this 1200 moves more like a 1600 than any 1600 i know! If you plan to rebuild your motor or just want to spice it up a little, then i suggest you send me an E-mail and we can talk about working the heads you already have.Now lets say  you're on your first 1914cc motor with 8.5:1 compression, a 120 cam,1.25 rockers and it's time to think about the heads.i say  some of our 40 x 35 Pockit port heads. with dual springs,crommoly retainers,shimmed up for .100 over total lift at the valve.