Third fastest was former Ehrlich driver Danny Sullivan having his first outing in the ex-Bob Evans March 723 that had been updated to ’73 specification. Fourth fastest was Masami Kuwashima who wasn’t happy with his Holbay and fifth was Andy Sutcliffe who was showing that the Elden was a very competitive proposition despite loosing the last 15 minutes of practice when he ran out of petrol and was stranded on the circuit. Of the rest of the runners Tony Brise found himself right at the back when his Holbay failed after just three laps of practice, the car was immediately taken to Holbay where the engine was repaired with the car arriving back at the track only 30 minutes before the start of the heat.
Brian Henton’s GRD was also sporting the works bracing struts and Superhen used it to great effect to take pole for Heat Two as well as setting the fastest overall time on Thursday. Second quickest was lap record holder Ian Taylor from Tony Rouff, another modified GRD runner. Mo Harness took the fourth spot in his brand new March-Brown 733 sponsored by Modus, sharing the same time as Harness was the second DART GRD of Pedro Passadore another to find the modifications to his GRD beneficial. Further back Larry Perkins was getting the hang of the works Ensign after his first outing on Tuesday was curtailed by a small accident whilst Barrie Maskell was having a run in the ex-Tony Brise GRD. Right at the back Mike Catlow was not given a time due to RAC entry cock-up, his Elden had been setting some quick laps and otherwise would have started well up the grid.
Danny Sullivan was in trouble before the flag dropped for Heat 1 when his engine would not fire up and he had to sit and wait for a push start as the rest of the grid departed. It was Wilds who got away the best from pole hotly pursued by Jones, Kuwashima, “Teleco” (penalised for a jump start), Vermilio and Sutcliffe. Wilds still led at the end of the first lap with Jones sitting right on his gearbox, “Teleco” was next but falling away, then came Kuwashima, Sutcliffe, Vermilio, Gambs, Sheldon Buzaglo, Lewis, Fuller, Tyrrell, MacDonald, Santo, Sherman, Brise and Sullivan (recovering from his push start). Brise called into the pits on the next lap with his engine refusing to rev, after one more lap with no improvement he retired the March.
Jones pushed his GRD into the lead on lap 2 at Stowe and although he led all the remaining laps Wilds chased him very hard and took the lead back on a number of occasions around the back of the circuit but Jones always had the edge and took the win by 0.3 seconds. Sutcliffe took third after passing “Teleco” on lap 6, he started to close on Jones and Wilds but then dropped away to finish 5 seconds down. Unfortunately it all went wrong at the post race scrutineering when Wilds was disqualified for having a 30 thou oversized airbox aperture and Sutcliffe was also out when a loose pipe on his airbox meant it would not hold the necessary vacuum.
All of this moved Kuwashima up to second ahead of Vermilio, Lewis and Santo all of whom were well spread out by the finish. The penalised “Teleco” and Sullivan took tenth and twelfth despite a big spin by the latter at Woodcote. Buzaglo was a retirement when he went off onto the grass, also at Woodcote, the resultant moment causing some damage and retirement.
Henton made a super getaway at the start of Heat 2 (initially it was thought too well and he was penalised but this was overturned on appeal from Henton), Rouff slipped into second from Taylor and Harness. As the cars entered Woodcote at the end of lap 1 Rouff used Henton’s slipstream to take the lead he would hold, except for a few brief moments, for the rest of the race. Henton was second from Taylor, Wood, Harness, Gerber (who appeared to jump the start without penalty), Passadore, Wunderink, Friedrich, Perkins, Maskell, Musetti, Robarts, Catlow, Craven, Hilliar, Sedgley and Coen. Derek Lawrence crawled into the pits to retire with the clutch in his Ehrlich burnt out.
Lap 2 saw six cars break away at the front with Rouff leading Henton, Wood, Taylor, Harness and Gerber. Wood moved up to second on lap 3 but Henton pushed him back to third again on the following lap and Gerber left the group with a spin at Copse. Next out was Mo Harness due to a combination of a slow puncture and a non-functioning limited slip diff so by lap 9 the fight for victory was down to four cars, Rouff still led but Woods was trying both sides to get past whilst Henton and Woods were not really in the hunt as both were suffering from flat engines. Under the Daily Express Bridge Wood was trying everything he knew to demote the American but Rouff kept his cool to take the win by a second, Henton kept third despite suffering from bent valves in his Rolt engine, Taylor took fourth 0.2 seconds behind the GRD. Retirements included Barry Maskell who had been in the top ten until an ignition problem meant a pit stop and Friedrich who had been in a similar position on the first lap until he damaged his March with an off at Club.
The qualifiers for the final were the first 12 from each heat plus the next 12 fastest laps, this resulting in the following grid:
Wood | | Rouff | | Jones |
| Taylor | | Henton | |
Robarts | | Harness | | Kuwashima |
| Wunderink | | Passadore | |
Spitzley | | Vermilio | | Perkins |
| Catlow | | Lewis | |
Gerber | | Gambs | | Santo |
| Sherman | | Sheldon | |
Sullivan | | “Teleco” | | MacDonald |
| Maskell | | Buzaglo | |
Sedgley | | Crossley | | Craven |
| Hilliar | | Musetti | |
Friedrich | | Fuller | | Tyrrell |
| Lawrence | | Coen | |
There was a considerable amount of creeping before the flag fell and several cars seemed to jump the start although only Johnny Gerber was penalised. GRD men Jones and Rouff led the rest and entering Copse Rouff dived into the lead chased by Jones, Wood, Kuwashima and Henton. Woodcote saw Wood make his move and pass the two leaders, Rouff kept second from a huge group consisting of Jones, Kuwashima, Henton, Robarts, Passadore, Taylor, Perkins, Wunderink, Harness, Gerber, Vermilio, “Teleco”, Lewis, Buzaglo, Maskell, Catlow and Sullivan, the rest followed further back. For the next five laps there were numerous place changes as positions began to settle down, Rouff moved back to the front with Jones pressuring him hard, Wood in third headed Kuwashima, Henton, Gerber, Perkins, Robarts, Vermilio and Taylor all tied together. There was a gap back to the next group, “Teleco” headed Maskell who was moving up well, next came Buzaglo, Wunderink, Harness who was recovering after a spin down the field on lap 3, Lewis, Santo, Sullivan, Spitzley and Catlow. The next bunch were further down the road, Craven led Lawrence, Musetti, Sherman, Crossley, Gambs, Passadore another spinner, down from sixth on lap 3, Sedgley, MacDonald and Hilliar.
During lap 6 Rouff, Jones and Woods pulled slightly away from Kuwashima who was beginning to go backwards and was soon passed by Gerber who then pulled himself onto the tail of the leaders. With no apparent difficulty Gerber then proceeded to pass the three cars in front of him and on lap 10 the Brabham was in the lead. Gerber soon pulled out a small gap to the others who weren’t too worried as their pits advised them of Gerber’s jump start penalty.
For the last ten laps it was a three way battle between the GRDs of Rouff and Jones and the March of Wood with the GRDs doing the leading as Wood watched and waited for a mistake to allow him to get ahead. On lap 19 Jones moved up to second and towed up to Gerber with the intention of passing the Mexican and letting the Brabham act as a buffer. Lap 20 and Jones tried for the lead at Becketts, unfortunately as he dived inside he hit a patch of oil and spun causing Rouff and Wood to take avoiding action which split them up. Gerber took the chequered flag first but dropped to seventeenth with his penalty, thus Rouff took the win from Wood with Jones recovering to third and just holding Henton off at the line who was again troubled by bent valves. Harness did well to take fifth after his spin from Kuwashima who was hampered by an engine that was loosing power.
Amongst the non-finishers were Perkins who spun at Becketts and was collected by Vermilio, both cars retiring on the spot. Robarts had been right behind Henton but he spun on the grass by the pits and stalled his engine, the subsequent push start saw him excluded from the results. Maskell retired with a faulty fuel pump on lap 19 having been sixth at one point and Lewis and Sullivan made contact at Copse on lap 9 with both cars being rendered hors de combat.