poor performance

[dbsupra]

I have a 1989 supra with a factory rebuilt PCM 351 engine with a Holley 4 barrel carb. the problem I'm having is the engine runs and performs great until the secondarys start to open then the engine boggs and will not go over 3 thousand rpm, I have tried adjusting the float level a couple of times the second time seemed to work the best but still bogged when it got into the secondarys, The engine has a distributor with points they don't look to bad Anybody have any ideas on what I should look at next, any problems changing it over to a elctronic ingnition, Is a holley card the best for this engine. There is no back firing at all it just seems that if you go past 1/2 throttle it's like pushing on a marshmellow and the boat will slow down hard on fuel.

[Jango]

Sounds like your secondaries are not getting fuel or more likely butterflies not opening, causing too much fuel. Could be a vacumn leak.
I prefer Edelbrock carbs (mechanical secondaries).