GRIND NO.

SEAT DURATION

.050” DURATION

CAM LIFT

LASH

APPLICATION

66-15

264

217

.262

I .015

E .017

ONE STEP UP FROM STOCK.

67-18

268

222

.289

I .018

E .020

1275-NEEDS PERFORMANCE SPRINGS

685-16

274

230

.295

I .016

E .018

SPRINGS & PORTED HEAD RECOMMENDED.

70-9

280

228

.263

I .009

E .011

HOT STREET 9:1, SPRINGS & HEADER.

70-10

280

228

.278

I .010

E .012

HOT STREET 9:1. SPRINGS, HEADER, REWORKED HEAD.

71-15

284

235

.290

I .015

E .017

AUTOCROSS 9.5:1 SPRINGS, GOOD HEAD, & WEBER.

715-18

286

242

.302

I .017

E .019

AUTOCROSS 10:1

SAME AS ABOVE.

72-10

288

235

.290

I .011

E .013

AUTOCROSS 10.5:1

SAME AS ABOVE.

75-15

300

250

.297

I .014

E .016

RACE GRIND. 11+:1

SAME AS ABOVE.

75-12

300

250

.323

I .013

E .015

RACE GRIND. REQUIRES BETTER HEAD THAN ABOVE.

M77-13

308

255

.321

I .014

E .016

FULL RACE APPLICATION 45-7500 RPM. 12+:1

765-14

306

261

.341

I .014

E .016

RACE. 12.5:1 REQUIRED

77-12

308

263

.348

I .014

E .016

RACE 13:1 MAX FOR PREPARED 948cc, MUST DYNO TUNE.

775-18

310

268

.380

I .022

E .024

RACE. WORKS BEST FOR 1275-1440cc ENGINES.