Random InfO: - rectangular intake ports, W 61mm x H 39mm - oval exhaust port, W 38mm x H 33mm - int. valve 33mm dia. - exh. valve 28mm dia. - lifter dia. int/ext. 28mm -1SZ-FE shimless bucket for 1G 3S heads: Part Number Lift 13751-23030 5.12 13751-23040 5.14 13751-23050 5.16 13751-23060 5.18 13751-23070 5.20 13751-23080 5.22 13751-23090 5.24 13751-23100 5.26 13751-23110 5.28 13751-23120 5.30 13751-23130 5.32 13751-23140 5.34 13751-23150 5.36 13751-23160 5.38 13751-23170 5.40 13751-23180 5.42 13751-23190 5.44 13751-23200 5.46 13751-23210 5.48 13751-23220 5.50 13751-23230 5.52 13751-23240 5.54 13751-23250 5.56 13751-23260 5.58 13751-23270 5.60 13751-23280 5.62 13751-23290 5.64 13751-23300 5.66 13751-23310 5.68
I believe it is, but you might wanna PM Mafix to make sure. I know the Yamaha casting number on my 1g 3sge head is the same as on the 1sgte head.