Hey guys,
I want to rebuild my 305, so i'm just trying to figure out some of the main expenses to do this. So far, i'm going for higher compression hyperreutectic KB pistons (i don't need forged, trying to keep expenses down) which will bring compression to about 9.9:1. Of course i'm going to change all bearings. I'll also be getting a nodular crank and those GMPP PM connecting rods. I'm just trying to get decent strength and performance without going with forged parts. I also want some reliability with the power, so would you suggest boring to be sure the cylinders are nice and round? And should I get the motor balanced? There's 80,000 miles on the motor now, so i'm just wondering if I should go for the boring (I'd like to, but once again, tight budget). How much would a good machine shop charge for overboring? Balancing? I'm sure every place is different, but I just need an idea. Thanks guys, I appreciate it.

 

If i was going for performance, i wouldn't rebuild a 305. Find a 350 for $100 and start with that. Parts are much cheaper for a 350, so it will cost the same. But you will have about 15% more power just from the bigger engine.

 

I know I should go for the 350, but I'm not going to. I'd love to have a 350, but then i'd just have to get new injectors, which will just add to the expenses. I know i COULD use the 19#'ers, but I'm sort of the "do it right" type of guy, so I'm just going to stick with the 305. And the question still stands.

 

Besides, I don't trust junkyard motors, so not only would I have to buy it, I'd want to bore it out. Which isn't a bad thing at all, i'm just saying, I'm trying to keep the price low.

 

If you're dead set on the 305 I think I would stick with the stock crank and rods that are in the motor, unless they are defective. Then you wouldn't need balancing, either. Then take that money you would have spent on balancing and crank & rods and get some decent heads & cam. I would get it bored and honed while it was apart because it just seems silly not to while it's disassembled. And since you're the "do it right" type of guy......

 

i'd spend my money on machine work not new parts. get the parts you have machined so they're round, straight, true, or whatever applies. run the stock crank and rods. get new rod bolts from arp and have the rods resized. if i were set on buying new pistons i'd bore it for sure.

 

Thanks a lot for the ideas guys. I really appreciate it. Always open for more if anyone has any.

 

For heads and cam, I already have the WP torquer heads, and I have a Hot Cam sittin in the garage that I still need to make use of. I figure if I get the new pistons after boring, i'd have more to work with for the hot cam. If I bore, I think I would go for .06 over, unless you think i shouldn't go for that much. About how much would boring run me anyway.

 

It'll be a couple hundred for machine work to do everything. Price and quality depends on where you go to get it done. Enginekits.com has 305 rebuild kits for $399 and a bunch of other stuff. http://www.enginekits.com/catalog.pdf

 

The Hot cam is a good start, but more than likely you'll have to tune the ECM for it.

Don't have any more bored out than needed. If it only takes .020" to clean the walls, then only get that done. Removing material from the cylinder walls just makes them more prone to heat up easier and become out of round.

The heads seem OK, but are they 305 heads?

 

I know about the ECU. I figure I'll just go through Ed Wright at Fast Chips. I hear he does good work. As far as the heads go, they are the 305 torquers (58cc combustion chamber). I just hope the chip will work out when all is said and done.

 

I too think that you should use the stock rods. Another thing to think about before boring is is the cam bearing hole drilled in the center, if not the cylinder walls wont have been bored correctly from the factory (the measurement for this is taken of the cam holes as I understand). If this is the case deffinitly don't have it bored more than you need to, a good machine shop will tell you. As for the price of boring, I paid something like $30 a hole with the hone.

 

Cool... thanks for the input guys.