Small Block & Big Block Chevy Specific Mouse & Rat Motor Discussion & Conversions

Help me pick a path

Thread Tools
 
Search this Thread
 
Old Jun 12, 2018 | 08:52 AM
  #1  
WisT02ws6's Avatar
Thread Starter
9 Second Club
 
Joined: Mar 2011
Posts: 22
Likes: 45
Default Help me pick a path

I currently have a 68 Firebird with a 73 454 and TH350. The person I bought the car from had no clue as to what was done before him, so I have been working on ID'ing what I am working with. So far I have the following:

Cam of some sort, appears to be flat tappet with hydraulic lifters
049 Heads
Harland Sharp roller rockers
Holley Street Dominator low rise intake (Old school part number #300-3 701R-3)
Holley 800CFM double pumper (List 6213)
2 inch unknown brand headers

I had the car on a Mustang chassis dyno and it made 297whp/411wtq so I am assuming the cam isn't very aggressive (has a nice lope though) and its a low compression smogger.

I was thinking about swapping the motor for an aluminum 5.3/4.8 LS motor with a carb for now. The pros to me are:

Reliability
Gas Mileage
Weight
Same HP?

I'm looking for open opinions on whether I should keep the BBC and start researching a build for that (H/C/I etc..) or if I should just move to the more modern technology and use that as a base for a build.

The car is a weekend cruiser/warrior, will see the track maybe 5 times a year. Budget is the same for both, $4000.

Any and all input is welcome!
Reply
Old Jun 13, 2018 | 07:00 AM
  #2  
biketopia's Avatar
TECH Fanatic
5 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: May 2017
Posts: 1,474
Likes: 101
From: Warrenton VA
Default

I'd h/c/i the BBC. I love LS swaps, but also absolutely love a good built BB. My brother has a 80 leman's wagon with a built iron headed 496 in the 600hp range, does 11's in the quarter, is totally streetable and gets mid teen's mileage wise when we take it to cruisn' OC with a TH400 and 3.5x's in the 9inch. 4k will go a long way with what you currently have, especially if you scour swap meets and classified ad's. The LS swap you'd need a hand full of swap parts, ignition controller, headers/new exhaust, swap torque converter/flex plate, wiring, motor mounts, hoses, possibly a radiator, misc fittings and hardware, the engine, then you'll probably want to put a cam in it while it's on the engine stand, and re seal it just to be sure. Swaps tend to snowball, even seemingly simple ones.
Reply
Old Jun 14, 2018 | 01:42 PM
  #3  
adk61's Avatar
Teching In
 
Joined: Mar 2018
Posts: 40
Likes: 0
From: north of the T.O.
Default

agreed... no replacement for displacement... especially seeing you're on a tight budget!! $4k will go a long way to build a BBC that you already own VS buying and modifying an LS... the LS stuff is modern and cool but more costly as BBC parts are everywhere!!
Reply
Old Jul 18, 2018 | 05:20 AM
  #4  
Jacobs1585's Avatar
Teching In
 
Joined: Jul 2018
Posts: 10
Likes: 0
Default

great thread.
Reply




All times are GMT -5. The time now is 09:34 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE