well guys i fianally found a 454 out of a 80-90 something truck, i was so excited to have found one that i forgot what year he said it was. anyway what are some of the things to look for on this block? its a complete motor but im just mostly interested in the block. like what year did they stop casting in the mechanical fuel pump boss and other things like that. and also will all year big blocks heads interchange? and do they make a big block vortech? i dont want one but just asking. i know a little about sbc but im new to the bbc world. are their any websites or something devoted to big blocks. as wonderful as the website is i couldnt find much info on big blocks which makes sense since a big block was never a factory option for a 3rd gen. thanxs guys.

 

An 80's BBC isn't the same as a 90's BBC. In 1991, they became a Gen V block. If it's an older block, it's worth doing something with it. Ditch the cast iron intake and peanut port heads. A 90's block is a boat anchor until you get into the 96+ Mark VI blocks.

The Gen V block has no provision for a mechanical fuel pump.

Mark IV heads will not easily fit onto Gen V blocks. The coolant passages don't line up properly.

Just about everyone who uses a BBC for a swap engine uses the older Mark IV casting including my aftermarket Dart block.

My 91 454SS has a Gen V block and it's one of the worst BBC engines GM ever produced. Good thing it only lasted from 91-95 or 96.

 

does it matter if you get a mark v block if you where going to get a complete new rotating assembly and heads or is the block itself part of the problem? thanxs stephen i appreciate it.

 

For some people, the Gen V block isn't bad. I'd guess and say over 90% of the aftermarket is still geared towards the older Mark IV block so that's the most popular.

The Gen V block isn't popular because it doesn't have a mechanical fuel pump boss. It was the start of the one piece rear main seal so all the old flywheels and flexplates won't work. Mark IV heads won't fit unless the proper head gaskets are used to prevent coolant leaks. It has terrible peanut port heads with small rocker studs and a non adjustable valve train.

The Mark VI block is considered the Vortec block. It has a roller cam, cast timing cover and lots of other improvements. More and more aftermarket parts are gearing up for this block. More than what was ever offered for the short lived Gen V block.

The Gen V engine in my daily drive was rated at 260 HP. Based on a power to weight ratio from dragstrip results, I'm pushing close to 300HP now and around 400 pounds of torque. It wouldn't take much to get it closer to 400HP but knowing what to do would help. Personally, it would be a lot easier to just drop in a Mark IV engine if I wanted to bump up the power level. I almost have enough parts to put together a 500 HP 469 which would be easily streetable. With the 4.10 gears in the truck and 300 HP, I can already smoke the tires if I need to. 4600 pound 1/2 ton truck that has run high 14.9 at altitude with just the engine and also ran a 13.2 with NOS.

 

well good news, i just called the guy again to ask what year it was. its an 86 so i guess im in ok shape then. hopefully going to pick it up tomorrow. thanxs again

 

Find out what casting the heads are. 049 is the most popular and have good potential although there isn't really a bad Mark IV head.