It's not the strength of the bolts that concern me,but the strength of the aluminum intake threads that I don't like.JMO.

I use a strap through the valley under the carb pad. Like one of those axle straps. Need one long enough. I've used that for years on my BBC even with sheetmetal intakes. With all acc. on the front of the motor its a perfect balance.

engine lift plates
 

hey olds 48. i like the way you think. infeel the same way as you. its the threads i dont trust not the bolts. good looking out chevy art

engine leveler for me...i had a speacial plate made to cover exhaust port on both sides of the head...Plus this hoist set up is a must for blower and tunnel ram engines.

I use an engine plate with a alum intake on my iron block alum head 496 with the trans atached. No problems I use the ARP carb studs to hols the plate to the intake.

Personally I'd never use one even though I've seen people put allot of weight on them but it would be my luck that the one time it failed it would be on me.
I built a load leveler and use grade 8 3/8 bolts, bolted directly to the back and front of the heads, using the intake bolt holes is another no-no in my book too.
JMO, Charles