Again thanks for the advice all jumped and explained it really helped a lot. I would not have done this in just over a year with FABO great group of folks appreciate it. Been following builds here since 2010.
Here’s the thing, there are several companies that offer a 1.6 roller rocker but they do not all exact lift the valve a true 1.6 mathematically. Or in actuality. Is the differences in the contact point of the roller tip the push rod contact point and the frog buckram point and the differences between them, additionally, pushrod length also has a play in this. Double check to see what your actual lift is.They are true 1.6 ratio roller rockers red and blue in picture. Stock are actually below 1.5. checking cam spec valve lift I'm now 526 intake and 540 exhaust. This cam is @107 rather than 110 so has overlap. For sure need to go to 3.73 rear gear. I fixed the tachometer tonight pulled out of loom and wrapped in foil tape. Also put that inside a 1/4 vacuum hose ran through one of the plugs it used for firewall insulation. Then checked no RFI issues tach is steady at idle. Speedometer same issue fixed tomorrow. Ran it up first gear 4500 holy cow and into 2nd before I chickened out. She is ready to go for sure. Just needs miles like you said rumble fish. Temps still right at 190 or lower very pleased with AC I needed it down low Oklahoma is HOT.
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According to build sheet and what I and builder did it is as specified a 1.6 ratio. The stock push rods were short so they were changed out and measured for correct length and what we wanted to accomplish. Would not have used them anyway as pretty old as they were old tired looking rocker assembly.Here’s the thing, there are several companies that offer a 1.6 roller rocker but they do not all exact lift the valve a true 1.6 mathematically. Or in actuality. Is the differences in the contact point of the roller tip the push rod contact point and the frog buckram point and the differences between them, additionally, pushrod length also has a play in this. Double check to see what your actual lift is.
What is the cam card saying for it’s lift?According to build sheet and what I and builder did it is as specified a 1.6 ratio.
Of course, there’s no other way. ;)The stock push rods were short so they were changed out and measured for correct length and what we wanted to accomplish.
As in the old/OE rockers?Would not have used them anyway as pretty old as they were old tired looking rocker assembly.
Large thumper cam and things have been changed were going to manual choke that's solved and the why. Getting rid of the vacuum advance on the distributor got a plate to install. It's driving great it really does not need a choke but since it's there manual if I need it just in case cable will be there. I changed the power valve 3.5 rear jets to 84. A/F sensor reads right around 11 to 11.5 idle but will adjust the idle metering screws out a smidge now. Driving A/F sensor is showing 11.5 to 13.5 it's a good average of 12.5. Power valve was 6.5 not bad but the 3.5 is a huge success. Matches the vacuum now of cam. Timing I'm at 18 degrees and total timing at 35. It's very snappy now and driving great best I have tuned it since I got her up and running. We're I to purchase carburetor again I would have gone non choke 750/850. Distributor would have had no vacuum advance from the start. Lessons learned and I can argue why you don't need those things on a hopped up strip street car driven on cruise in and for fun.how much initial timing do you have on the engine?
I know you have a thumpr cam is it the small, mid or large one. If someone told you you would get 13in of vacuum with the mid or large one, yeah not gonna happen at a typical idle level. The large one is 240+ at .050, not "idle" or vacuum friendly.
Have fun with it. Good to read it is broken in and running strong.