my son and i have a 1986 iroc-z, and we had gas pour into the 305 fuel injected motor from a bad fuel regulator. we pulled engine and found that the block is original but the heads are not. we are planning on redoing the whole engine. we want to beef the horse power on it but also pass smog in california. should we keep the original engine block and build on that? or should we order a crate engine? we have no engine building experience so we know we are going to get ripped at the machine shops around here> willing to listhen to replies and go from there. its going to take several months to get money organizes so dont panic if we havent posted in a while. thank you

 

Is there anything wrong with the block? Did you see some scoring or anything? If you want to keep it original, rebuild the block. Unless you buy a newer style motor, like an LS, it's going to be cast iron just like that one. You can always upgrade the heads and intake manifold/runners if you're looking to keep the same fuel injection system. You can also buy some tuning equipment and make some adjustments if you have the desire for that. What HP are you trying to get?

 

well, when we dropped the oil out of it we had two quarts oil and seven quarts gas come out. we plan on keepin the stock engine block but want to get it machined clean . we looked at one rod bearing and it showss a little copper on it. we havent completely tore it down yet. we would like to stick a mild cam and some awsome heads on it to get more horse power. we can buy a crate engine, but figured it might bring down price value of car.

 

300 hp is good enough

 

Edelbrock makes a 50 state C.A.R.B. accepted top haft.Not cheap,but for moderate gains is not bad.Then it is a question of what you have to do to the bottom end.

 

I think you could probably get 300 HP no problem while still keeping the original block and same stroke. Headers, intake, better heads, larger injectors, and a good tune should get you there or really close. Here's a thread that has some interesting information as far as add-ons go. They refer to a 5.7 but you should get a basic idea of what gains you could/should get:
https://www.thirdgen.org/forums/afte...s-any-one.html

 

thank you ransford, called everybody today and they dont make 305 performance engines. only person was chevy performance but the engine was only 190 hp. almost ready to get a 350 and stick it in there but i saw your post so im going to check it out.i guess two hundrerd fifty to three would be good enough. ill check out the site and see if i can make sence out of it.

 

Here's another link for you, specifically with a 305 and relatively stock: https://www.thirdgen.org/forums/tpi/...ne-rwhp-s.html
Once you make some decisions, start a build thread and post some pictures. There are a lot of people on this site who have vast amounts of knowledge specific to engine building for HP gains, and that might be a good way to get specifics on what cam, heads, etc. you might need.

 

Thank you for the reply ransford, your time and help is very much appreciated. We are going to use your help and look into the site and get some money saved. Once we get some pictures up and posted can we post here or should I start a new thread?

 

I would start a new thread under the engine swap, tech/general engine, or tpi section. The guys doing engine swaps know their stuff, and the tech/general section will get you good info as well. Good luck with the build! Once you get it started, I'll follow it to see how it goes.