Holden 355 - would you lock the timing with this combo?

[BasicQ]

Possibly, and/or using a very early opening power valve. Maybe COMO can respond.

I'm thinking the 66 main jets would cause bucking/surging prior to the power circuit coming in...or a hotter running engine.

I would also think a lean surge is quite possible with only 66 MJ in a 750 with a single plane manifold. 650 Holley comes with about that size MJ. I think the clue as to why 66’s in the front lies in those extra holes the carby guy drilled. Need to know all the critical dimensions though,

IFR
MAB
IAB
Emulsion sizes (and are there three now?)
PVCR
Pri MJ (we know is 66)
Sec MJ

Quite difficult to look up as these 4779 had quite a few variants.

[COM081]

Sadly fellas I don't have that level of detail on the carby other than being able to confirm there are now 3 emulsion holes. Tuner said it was well rich up top, dyno chart confirms that. Press in air bleeds and drilled emulsion chamber might explain the small jetting?

Idle is also higher, 1100 in N, 900 in gear, up a couple hundred post tune. Thinking about it, temp increase is at idle. Has gone from 85-90 to 90-95. Didn't see 100 and did sit in some shitty traffic for a good while.

Besides the increase in temp fuelling seems good. No surging and transition from part to full throttle is crisp. Loves to rev. More kms needed though to get a good feel for it.

Hesitation reared its head again last drive though intermittent this time and coincides with an electrical issue I need to resolve.

A few things have rattled loose as can happen with a new build, positive battery stud in firewall being one of them. That lead to a no-go scenario, quickly diagnosed with a test light but yet to pull back carpet, underlay etc to properly check the connection. I think/hope that will clear up the stumble.

[BasicQ]

Sadly fellas I don't have that level of detail on the carby other than being able to confirm there are now 3 emulsion holes. Tuner said it was well rich up top, dyno chart confirms that. Press in air bleeds and drilled emulsion chamber might explain the small jetting?

Idle is also higher, 1100 in N, 900 in gear, up a couple hundred post tune. Thinking about it, temp increase is at idle. Has gone from 85-90 to 90-95. Didn't see 100 and did sit in some shitty traffic for a good while.

Besides the increase in temp fuelling seems good. No surging and transition from part to full throttle is crisp. Loves to rev. More kms needed though to get a good feel for it.

Without knowing if your carby guy opened up or changed any of the orifice sizes of what I mentioned above it’s hard to know. Just as long as things are balanced so the 66’s that leaned out the top end didn’t overly lean part throttle and the spread between primary and secondary didn’t end up too much, or at least area of primary MJ + pvcr are close to equaling secondary MJ area.

[gtrboyy]

Nice results & will be be fun with those figures.