351 Roller Conversion Thread

[Pro351]

New cam installed, along with a roller timing chain:

[Pro351]

Side note: for anyone replacing the camshaft in their Prostar of the same era as mine... the pylon needs to be removed. There isn't enough clearance to remove the cam with the pylon in. There are two U-bolts (4 nuts total) and it comes right out. The upper U-bolt nuts are accessed through the access hole underneath the front seat by the battery.

[Pro351]

Retrofit linked roller lifters: Howards Cams # 91260

Pushrods: COMP Cams High Energy Pushrod Set Ford 351W w/Retro-Fit Hydraulic Roller Cam
Part Number: 249-7823-16

Both installed.

[Pro351]

Scorpion 1.5 ratio pedestal mount roller rockers, torqued to 20 ft lbs. Pedestal mount use the existing 5/16 holes.

[Pro351]

Edelbrock Performer intake and Quick Fuel M-650 carb.

[waterlogged882]

Good looking engine.

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[Pro351]

Topped off the GT40P heads with a nice set of valve covers. (Had to remove oil baffles to make room for the rockers). These valve covers aren't considered "tall" and still were tall enough to accommodate the higher lift cam and roller rockers. Very nice quality set.

[Ironhorse]

That looks great! My OCD wants you to change those few rusty bolts though.

[Pro351]

That looks great! My OCD wants you to change those few rusty bolts though.

I agree. I bought so many parts... that when I was putting the engine back together, I remembered that I forgot to buy new head and intake bolts. I plan on getting some black paint to touch up the bolts with a small paint brush.

[Pro351]

UPDATE: So after several hours of working on this engine... it was time to fire her up. I did a final check of all the fuel lines, wires etc. Turn the key, and the engine just cranks and cranks... doesn't even attempt to fire. Check fuel pressure, good. Check spark, no spark. Prior to trying to start the engine, I changed the coil to the Pertronix Flame Thrower 2. Thinking maybe that coil is bad, I put the old coil back in. Still no spark. I checked for spark directly from the coil wire, thus bypassing the distributor and plugs... still no spark. Checked voltage at coil with key on, 8v. Proceeded to check voltage starting from ignition, 12v. Then checked the ING circuit breaker and all wiring, 12v. Checked all grounds, good. Then applied 12v directly to the coil (+ post) from the battery, still no spark from the coil. Removed tach wire (gray wire) thinking maybe its a ground problem, still no spark. I then removed the red wire that goes from the ignition module to the coil and checked the voltage... 12v!! I then reinstalled the red wire and rechecked, it dropped back down to 8v. It appears my electronic ignition module is bad and causing a serious drop in voltage. Ordered a new Pertronix Ignitor 2 Ignition module which should be here in about 3 days. Will install and check for spark. Nothing to do with the rebuild... just bad timing for something to go wrong. Oh well... this is life. Will update when new ignition is installed.

[d2jp]

Great looking top end build. My suggestion based on experience with the OEM Prestolite distributor using a Pertronix module….bite the bullet and purchase a new Pertronix distributor. It’s a nice upgrade and worth the difference in cost of that module you’ve ordered assuming you can return it for full refund. If you stay with the Prestolite and need a spare module (or two) let me know, I will make you a deal. I always kept a spare module onboard and one on the parts shelf. Replaced with new distributor and have never looked back so I have a couple of modules, one removed known good and one brand new.

[Pro351]

Great looking top end build. My suggestion based on experience with the OEM Prestolite distributor using a Pertronix module….bite the bullet and purchase a new Pertronix distributor. It’s a nice upgrade and worth the difference in cost of that module you’ve ordered assuming you can return it for full refund. If you stay with the Prestolite and need a spare module (or two) let me know, I will make you a deal. I always kept a spare module onboard and one on the parts shelf. Replaced with new distributor and have never looked back so I have a couple of modules, one removed known good and one brand new.

Thanks. I almost bought a new distributor and probably should have for all the money I've spent on this engine upgrade. But I decided to buy just the module. You make very solid points. I try to repair things that may leave me stranded on the water in hopes of preventing that. I still might buy a new distributor and keep the module on board like you. That module from Skidim was $230! But I found it on Summit for $150. So I'm thinking in the near future, install a new distributor and keep that Summit module in the glove box just in case.

[d2jp]

The EI module for the Prestolite distributor is part (PNX-91589). A new Pertronix distributor, part number (PNX-D231801) uses module part (PNX-D500700). In other words the module you purchased is of no use to you if you decide later to buy a new distributor. But if your original Prestolite distributor is working as it should, the springs are good,etc (and replacement springs are available and around $10) and achieving full advance - no need to spend money just to change parts. And I will give you a deal on a module to keep as a spare if you need it.

[Pro351]

The EI module for the Prestolite distributor is part (PNX-91589). A new Pertronix distributor, part number (PNX-D231801) uses module part (PNX-D500700). In other words the module you purchased is of no use to you if you decide later to buy a new distributor. But if your original Prestolite distributor is working as it should, the springs are good,etc (and replacement springs are available and around $10) and achieving full advance - no need to spend money just to change parts. And I will give you a deal on a module to keep as a spare if you need it.

Good call. Upon researching, I did notice the part numbers are different. I'll let you know about the module... I'm still debating if I should purchase the Pertronix Distributor. My Prestolite is functioning fine... it's just that everything on this engine is new (even the lower end)... except the distributor.. Do you have any spare PNX-D500700 modules laying around?

[d2jp]

Good call. Upon researching, I did notice the part numbers are different. I'll let you know about the module... I'm still debating if I should purchase the Pertronix Distributor. My Prestolite is functioning fine... it's just that everything on this engine is new (even the lower end)... except the distributor.. Do you have any spare PNX-D500700 modules laying around?

Unfortunately I don't have a spare but need to order one to keep on my boat. I picked the Pertronix distributor based on price and availability -Summit Racing had a great price for Next Day. Doing it over, I’d look at Mallory and Davis (DUI) too. They are more $$$, but might not be prone to module burn-out like Pertronix can be. If your engine was running fine before the top end refresh id stick with what you have, then decide later on if a change is needed. Great looking engine!