Hi Guys, I have some distributor questions I'm hoping ya'll can clear up for me. I am running a 302 HO block with Ford GT40X aluminum heads, Edelbrock RPM intake and Holley 600 carb. I have the Duraspark distributor and ignition box with the blue tab (I believe there is one with another color tab). I don't think I am running a roller cam because I do not have roller rockers in the head. They are the regular spring valve set-up. The dizzy is worn out and I want to get a new one. I have been reading on the forum that an 85 Mustang GT-manual transmission dizzy will fit and has a steel gear. Question #1 - can you run a steel gear dizzy on a non roller cam? If not what dizzy should I get that has the iron gear. Question #2 - will this dizzy work with the blue tab box or do I need the other. I may also go to the Streetfire box for better performance and less cost than the full MSD. As I am having a complete re-wire done I am also considering converting to an HEI distributor for less wiring. I have read there are fitment issues with the bigger cap. Right now I have a 14 inch air cleaner. Other than having to go to a smaller air cleaner do you see any other issues with the set-up I have. Any suggestions on a quality HEI dizzy. I've been looking at Davis Unified Ignition and MSD but there is that high cost with them. I don't mind paying for quality but if they aren't any better than some others that are cheaper....... Thanks for your input. I am going to go and buy a new bottle of Tylenol now
I have the same intake and started with an HEI and there is clearance issues, had to do a little grinding on the intake, but have since switched to the pertronix igniter 2 and works well. do not buy the Summit brand they are junk
You do not want to run a steel gear on a std cam... AFAIK dist for any other vehicle with with 5.0 and Duraspark can be used...
What year is your engine? If it is in fact a 302 HO it should have a roller cam and have the firing order 1-3-7-2-6-5-4-8 of the 351W. Roller cams do not necessitate having roller rockers. You probably have a 302 with a roller cam and stock non roller rockers. The 351W firing order is the indicator. If that is the case, Krazy Comet is correct and you can use any Dura Spark dizzy from any 5.0L. I run the `85 Mustang manual trans application. I personally do not like the look of the big cap HEI distributors. Just my preference. I have attached a much earlier photo of my engine compartment with the Dura Spark that has powered my Comet through several engine swaps for more than 20 years. I located the box just ahead of the windshield washer.
I'm not sure what year the engine is. The guy I got the car from 9 years ago was only able to tell me it was a 302 HO block from Summit. But my firing order is 1-8-4-5-6-2-7-3. So from what Hotrock is saying about the firing order it seems I do not have a roller cam then. Reverse question then. Can you use an iron gear on both a roller and non-roller cam. I've been leary about the HEI set-up. And from the responses I've gotten and seen on other posts I am going to stick with the Duraspark set-up. Any advice on where to get a quality "new manufactured" unit?
HUH??? Wha'd you give us, a Chevy order??? Ford small block firing orders are either 13726548, for HO 5.0 & 351 or 15426378 for the std 302/5.0 Lo-Po version... When dealing with iron or steel gears they MUST match the material of cam, no exception... From 1986-1991 Lo-Po Crown Vic, T-Bird etc 5.0 used a steel roller cam with the 15426378 pattern.. Trucks used same firing order with flat tappet cam till 1992... Easy way to tell what you have is measure a push rod, roller cams use a 6.27" rod while flat tappet is 6.80" or ½" longer...
Sorry, Sorry,,,,,I knew that firing order didn't sound right as I was typing it. I had someone read off a drawn diagram to me and it was obviously the wrong one. I'll double check the order when I get home this afternoon and respond back.
OK. The diagram was right. It was read to me clockwise instead of counter clockwise, my fault. My firing order is 13726548. So that should make it the HO block. Would that automatically mean it would be a roller cam and I can use the steel gear distributor. Can a non roller cam be used in that block? I don't think it is a stock cam. It seems to be a high lift cam with a lumpy idle. Again the previous owner was not big on exact specs.
Really no such thing as a HO block, roller cam blocks are same whether they were in a Mustang or grandma's Grand Marquis or a F-150... The difference in roller vs std blocks is the lifter bores are taller to accomodate the taller roller lifters, plus there are a couple bosses cast in valley that get machined and threaded to secure the lifter hold down spider.... Once introduced, same block was used in truck engines that still used a flat tappet cam(possibly without the extra spider boss machining, not necessary for std cam)...
