The Clifford intake is not good for the street especially on a 250 or smaller engine low compression,bad gearing & so-on.
Poor gas mileage,poor low & midrange.
You will need to slip the clutch more with that intake over an Offy.
Talk w/twisted6 for your head work suggestions.
Stock SBC springs can be 70-100 lbs @ the seat,IIRC?
If you are going with standard dished piston 250 I would look for a smaller chamber 194 head.
Go with a zero deck on your next engine.
Two cents thrown :-)
MBHD
I plan on building a similar motor soon (292). Want good drivabilty. Are you saying that an Offy 2x1 or 3x1 would be a better option over a 4bbl intake, or an offy 4bbl intake would be better over a clifford 4bbl?
I have quite a few option for used intakes right now and I'd like to select the best one. Plan on using a mild RV cam, split headers, TH350 trans w/ stock converter, 2.78 rearend. Would like to get the most bang for my buck. I'll probably look at head modifications down the road.
Built plenty of performance V8s, but seems like the rules change with I6s.
And for what it's worth on the topic at hand. Bad valve train geometry sounds like the main culprit of what was happening. I'm not sure what the difference is between the valves but you said your heads had SBC valves, maybe whoever originally built it was using the SBC rockers to compensate for valves with a different stem length.
I wouldn't be too concerned about a broke lifter. Probably just smoked your cam and lifters. I would put money down that said the rest of your motor is fine, unless you cracked the block. I've seen lifters explode a few times in V8s and none were catastrphic enough to ruin the engine or block. Might check the lifter bore for serious scoring though.
Take the cam out and rotate everything. I doubt it's froze. Probably just locked by the cam and lifters being out of alignment. Was there any head damage due to push rod dropping? If not, you'd probably be ok.
