From left to right are the stock iron heads... ...the Edelbrocks... ...and the TA Performance versions (the last of which has slightly larger valves). The combustion chamber shapes are slightly different, but they are all within 2 cc of each other. Ignition timing for best power was 32 degrees total with the stock heads, 34 with the aluminum heads....and the TA Performance versions (the last of which has slightly larger valves). The com These photos compare the different shapes of the spark plug holes on the Edelbrock heads...These photos compare the different shapes of the spark plug holes on the Edelbrock heads.. ...and the TA units. With the Edelbrocks, a little grinding would have been needed to clear the dipstick tube; you can see here that we plugged the hole after loading the pan with Lucas sauce....and the TA units. With the Edelbrocks, a little grinding would have been needed to clea We used E3 spark plugs throughout our test. The only thing notable about this is that the TA heads needed a cleanup tap run through the plug holes, while the Edelbrocks did not.We used E3 spark plugs throughout our test. The only thing notable about this is that the RPMStockEdelbrockTA PerformanceLB-FTHPLB-FTHPLB-FTHP2,2003881624301804271792,3003901714241864231852,4004021844231934251942,5004151984272034312052,6004232104342154372162,7004292204412274442282,8004342324482394512412,9004402434572524592533,0004472554662664672673,1004552684742804762813,2004642834832944852963,3004712964923094923093,4004773095013244993233,5004833225083395063373,6004883445133525133523,7004913465163645183653,8004923565183755223773,9004943675193865233884,0004953775193955233994,1004953865184055234094,2004923945184145234184,3004894005184245244294,4004854065194355264404,5004814125194445274514,6004794195184535264614,7004784285154615254704,8004764365124685244794,9004744425084745224875,0004694465054815194945,1004624495024874144995,2004564514984935085025,3004504514944985025065,4004444574885014965105,5004384594795014895125,6004314594684994815135,7004194554584974725125,8004084514444914625115,9003954444334864525086,000383437419479441504AVG452349483379489385 SOURCESARPJMS Racing EnginesVentura, CAMonrovia, CA800/826-3045626/357-2718805/339-2200jmsracing.comarp-bolts.com  Lucas Oil ProductsE3Corona, CAPonte Vedra, FL800/342-2512e3sparkplugs.com951/270-0154 lucasoil.comEdelbrock Torrance, CAMSD Ignition800/416-8628El Paso, TXedelbrock.com915/855-7123 msdignition.comHolley Performance Products Bowling Green, KYPercy's High Performance270/781-9741Linn Creek, MOholley.com888/737-2970 percyshp.comHooker Headers (a Division of Holley)Rockett Brand Racing FuelBowling Green, KYGlenview, IL270/781-9741 (tech)800/345-0076800/465-5391 (dealers)rockettbrand.comilovemyhookerheaders.com  TA PerformanceJet-HotScottsdale, AZ336/447-2000480/922-6807jet-hot.comtaperformance.com « | 1 | 2 | 3 | 4 | View Full Article By David Freiburger Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!