Has anyone put a big cube gen 1 small block in a 4th gen f-body? How much do those blocks weigh compared to an LT1 block? Is the block longer than an LT1? any clearence problems with the shock towers? Any input is appreciated.

-Tony

 

The blocks should be just about the same physically. The biggest headache is putting a distributor back there under the cowl. Oh, you would probably need to use an aftermarket belt setup since the LT1 accessories won't work on a Gen 1 SBC, and I'm not sure how a standard serpentine setup would work in the 4th gen engine bay. Everything else should fit pretty well though.

 

Dont forget standard SBC motor mounts are slightly different than LT1 motor mounts too. Theres a few people out there with a Gen 1 under the hood. George Baxter switched over from an LT1 to Gen 1 last year, maybe Injuneer would have some info on it?

 

Is the gen 1 block cast iron or aluminum? Is the dart block a better alternative? What is the biggest cubes seen in a gen I small block? Biggest cubes in a Dart?

 

Well, with aftermarket blocks you can get iron or aluminum. One just costs a bit more than the other. As far as displacement goes, I think Bill Mitchel offers a 454 CID small block chevy that makes 600 horse power on pump gas. Not too shabby. Most people with Darts stay between 400 to 434.

 

You need to realize that NONE of your engine components will work with a Gen I? Heads, intake, computer, accessories, etc.? Some of the parts can be modified to work, but the whole thing is far from "plug-n-play". If you need to ask this question, it is probably something you shouldn't even consider! I don't know of anyone with a street or street/strip car that has done this. Probably because you can generate all the hp a 4th gen can readily handle with the LT1.

But to flesh out what others have said, the problem isn't the block, which has the same dimensions. The block will bolt up. There is everything from cast iron OEM production blocks to the "Bowtie" competition blocks from GM to aftermarket blocks. Both Bowtie and aftermarket blocks are available in cast iron or aluminum. The aluminum blocks are quite expensive.

If I were tired of the LT1, I'd swap in a Gen III.

Rich Krause

 

Well, i am not really tired of the LT1 motor... Its just that my end goal is to have an all motor car with a SBC with 454 ci or more. I'd like to have ~ 600hp to the wheels on all motor. I know that acomplishing this with an LT1 motor will be quite difficult on a 396 ci. I also would like to juice on top of this and from my understanding LT1 blocks are not that reliable due to cylinder wall issues, cost/ performance $. Also i just want to get rid of that heavy cast iron blcok... - Tony

 

Tony: you are talking a big budget project. It's quite do-able but very, very expensive. Are you planning carb or FI? That's a big choice that would need to be addressed right off. FI is definitely more streetable, but will cost at least $3,000 more than a carb. An aluminum SBC is 90-100lbs lighter than an iron block. Figure ~$4,000 for the block. See what I mean about high budget?

If you want a dynamite aluminum NA small block Chevy, I'd suggest the LS1/LS2 family as the starting point. Won't be cheap, but probably a lot less than 1/2 the cost of a gen I buildup.

Rich Krause

 

And it would be alot more drivable. Look at some of the 427 Gen. 3 motors coming out of places like Moore and Agnostino (sorry if I misspelled that). And, if you will settle for 600 hp with a blower or turbo, the goal becomes alot easier to reach.