What does hi perf mean on my big block

[4X4HIGH]

Probably the rarest engine would be the all aluminum Z11 427 engine that was based on the 409 with a longer stroke crank. GM only made 50 cars with that engine and only 20 more engines for over the counter sale.

 

[BadBob]

As duly noted, the Pass and HiPerf don't really mean anything other then it's a passenger car/truck block, and not a medium or HD truck block. Now a "10" or "20" (iirc, it might be 010 and 020) in there do have some meaning.

 

[LOGANSTANFORTH]

Oval Port.....
3367814541973-1985Open chamber
3462364541975-1978Open chamber ("peanut" ports)
3530494541970-1973Open chamber
3872702396 and 4271966Closed chamber
39043904271966Closed chamber3
9043904271966Closed chamber
3909802396 and 4271966-1967Closed chamber
3917215396 and 4271966-1969Closed chamber
3931063396 and 4271966-1969Closed chamber
3964280427 and 4541966-1970Closed chamber
3964290427 and 4541966-1970Closed chamber
3993820402 and 4541970-1971Open chamber
39992414021970-1972Open chamber
6272292402 and 4541971Open chamber

Rectangle Port....
38562083961965Closed chamber
3904391396 and 4271965-1967Closed chamber
3919840396 and 4271965-1969Closed chamber
3964291396, 402, and 4271965-1970Closed chamber
39642924541970Closed chamber
39940254541971Open chamber
39940264541971Open chamber
39960744541971Open chamber
62587234541971Open chamber
62729904541971Open chamber

 

[nvrenuf]

Oval Port.....
336781 , 454 , 1973-1985 , Open chamber
346236 , 454 , 1975-1978 , Open chamber ("peanut" ports)
353049 , 454 , 1970-1973 , Open chamber
3872702 , 396 and 427 , 1966 , Closed chamber
3904390 , 427 , 1966 , Closed chamber
904390 , 427 , 1966 , Closed chamber
3909802 , 396 and 427 , 1966-1967 , Closed chamber
3917215 , 396 and 427 , 1966-1969 , Closed chamber
3931063 , 396 and 427 , 1966-1969 , Closed chamber
3964280 , 427 and 454 , 1966-1970 , Closed chamber
3964290 , 427 and 454 , 1966-1970 , Closed chamber
3993820 , 402 and 454 , 1970-1971 , Open chamber
3999241 , 402 , 1970-1972 , Open chamber
6272292 , 402 and 454 , 1971 , Open chamber

Rectangle Port....
3856208 , 396 , 1965 , Closed chamber
3904391 , 396 and 427 , 1965-1967 , Closed chamber
3919840 , 396 and 427 , 1965-1969 , Closed chamber
3964291 , 396, 402, and 427 , 1965-1970 , Closed chamber
3964292 , 454 , 1970 , Closed chamber
3994025 , 454 , 1971 , Open chamber
3994026 , 454 , 1971 , Open chamber
3996074 , 454 , 1971 , Open chamber
6258723 , 454 , 1971 , Open chamber
6272990 , 454 , 1971 , Open chamber

Added spacing to make it readable

 

[LOGANSTANFORTH]

i just threw it up quickly so i didnt bother....

 

[original balzer]

The rarest big block chevy is this one

cast# CID years description
399204.....509.......70-71...4-bolt, Alum., CanAm, 4.5" bores, steel Cylinder liners

 

[4X4HIGH]

The rarest big block chevy is this one

cast# CID years description
399204.....509.......70-71...4-bolt, Alum., CanAm, 4.5" bores, steel Cylinder liners

Could be but it wasn't in a production car that the public could buy like the Z11 in the 1963 impala sport coupe.

 

[original balzer]

Granted but I didnt say rarest production car big block I just said the rarest big block.

There was actually quite a lot of them built but they got used up in the canadian american races.

I do belive however that it was offered as an option in 70 and 71 camaros, just a VERY expencive option. Tecnically Can Am cars are factory race cars so I guess they would be a prodution car.

Theres a 67-69 camaro version that was a little smaller with a 4.44" bore too.